- Dirt Road Magazine - Own A Jeep? (dirtroad.com)
Credits
Home
F.A.Q.
Media Kit
Cover
Vendor Catalogs
Jeep Rater
Show & Tell
Yellow Pages
Projects
Site Map
E-mail Us
Jeep Forum
Ask Grant
Features
Columns
Trial & Error
Classifieds
Trading Post
Back Issues
Links
©2008 Dirt Road Magazine


"I have a 1988 Jeep Wrangler Laredo, with a 4.2L/Manual. I am in the process of replacing the stock carb with the Mopar MPI system.  In the near future I will be replacing the exhaust with Borla headers and exhaust, as well as dumping the stock tranny in favor of the NV4500.  Finally I am going to be installing air lockers (with new 4.11 or 4.56 gear sets) in the front and rear to keep my existing 33x12.5" mudders from spinning.

My question is this:  Will the resulting torqe and unforgiving nature of the lockers be too much for my current axles?  If so, is there anything out there that I can replace them with and still keep the shift-on-the-fly(there is a lot of snow here in Tahoe)?"

The setup you desire would be pushing the limits of your current axle assemblies. A lot depends on your usage of the Jeep as to if or when the axles may fail. I don't know that I could really justify recommending close to 4 grand in custom axle assemblies unless you actually had a failure. If one of the axles does fail you, and you want to upgrade to larger components, Dynatrac (http://www.dynatrac.com) can build a custom Dana 44 front axle for you without losing your shift on the fly ability.


"I have a 1997 Cherokee Sport, with a 4.0 Auto. After sustained highway driving in my 1997 Cherokee Sport, I sometimes get a strange sound from the rear end when slowly pulling out from a stop.  Its a chattering sound, maybe like something slipping.  Of course when I took it back to the dealer, the problem didn't happen when they drove it.  I only have about 2000 miles left on the warranty, so I'm very concerned. I have the Up Country package installed. Any suggestions?"

My guess is that you have the factory Trac-Loc limited slip rear differential. Occassionally they will chatter during a turn. My advice would be to change the gear oil in the rear axle with the manufacturer's specified gear lubricant, and be absolutely sure to add the special Trac-Loc additive available from your dealer. This should solve the problem.


"I have a 1985 Jeep Cherokee, with a 5-spd manual. I discovered that I have a NP 207 transfer case. I have never heard of that, and was wondering if you had any info on it...is it good or bad...should I replace it...?"

The NP207 was standard equipment on early Cherokees and some early Wranglers. It doesn't have the most sterling reputation, but with proper maintenance, it shouldn't give you much grief. I wouldn't run out and buy an NP231 to replace it until when and if it breaks.


"I have a 1985 CJ7, with a 258/T5. I'm planning several upgrades for my stock Renegade. I'm trying to decide if I should swap the T5 for the NV4500 for the low gears, or keep the T5 and put the Tera-Low kit in the dana300.

The Tera-Low would be initially cheaper but would I be better off in the long run with the NV4500? I also plan to run 33" tires with either 4.11 or 4.56 in the axles. "

I think in the long run you'll be better off replacing your transmission with the NV4500. The T5 is pretty marginal even with the 258, replacing it with a very heavy duty transmission such as the NV4500 would eliminate a weak link and give you a lower crawl ratio.


"I have a 1998 Jeep TJ, with a 4.0/5-speed. I want to be able to do fairly serious rock crawling with my TJ. I intend to add 4" lift, 35" tires, a 4.3 Atlas II, ARB's front & rear, rear disks, and 4.88 or 5.13 gear sets. Sometime later, maybe add a Chevy 350 and NV4500 or 700R4. How will the stock axles hold up? Or should I go ahead with Dana 44’s front and rear? I realize that to go to 5.13's, I will have to change the Dana 30 in the front. Thank you."

If you complete all the modifications you have listed, the stock axles will have to go. Since the Atlas case has an extremely low range gear, coupled with a V8, the amount of torque sent to the axles could be 10 times greater than ever intended. You mentioned a desire to run 4.88 or lower gears, the lowest available for either axle is 4.56. If you want lower axle ratios than that, you'll have to swap both axles. Keep in mind that the lower the axle ratio, the "weaker" the gear sets are. This is due to fewer teeth on the pinion gear. For example, a typical Dana 30 front with 2.72 gears has 49 teeth on the ring gear and 18 on the pinion. A 4.56 gear set for the same axle has 41 teeth on the ring gear and 9 teeth on the pinion. In order to maintain durability while running low ratio gearsets, you have to upgrade to a heavier duty axle with larger gears. Either a Dana 60 in the rear and Dana 44 up front, or Ford 9" axles at both ends, or some combination of the two.


"I have a 1997 TJ, with a 4.0/Manual. How do I go about changing the oil for the front axle and rear axle? Also, the rear axle asks for a special Mopar additive. In looking around some auto stores, I've seem lubricant with something extra in it. Would this extra be the additive?"

Changing the oil in the differentials is very easy. Put a drain pan underneath the differential, remove all the bolts from the differential cover, then gently pry the cover from the axle to allow the oil to drain out. To reinstall the cover, remove all traces of silicone from the cover and axle, then use a degreaser (acetone works very well) to completely remove any oil from the mating surfaces of the axle and the cover. Apply a bead of silicone to the cover and bolt it to the axle. Remove the fill plug in the cover to replace the oil, when the oil level reaches the fill plug, it's full and you're done.

You need an additive for your rear differential because of your Trac-Lok limited slip. Carefully check the back of the bottle of gear oil that you buy and be certain that it meets the Mopar specs. If not, purchase the additive from your Jeep dealer.


"Will be purchasing a 4x2 Grand Cherokee Laredo. Seldom off-road, and only lightly, but was considering ordering the TracLok. What type of differential is the factory TracLok? Is it a limited-slip/posi-traction type unit? Does it really enhance off-road capability? Does it escape some of the on-road handling problems inherent in aftermarket diff's like the LockRight? I would like the added traction a locking differential would provide but without the on-road compromises. Any comments and advise would be greatly appreciated. Super site! Thanks. "

The factory Trac-Loc is a limited slip type differential. It's overall benefit off road is pretty marginal. It will help some initially, but the clutch packs tend to wear out very quickly. Considering the fact that you're purchasing a two wheel drive, ensuring that both rear wheels receive power in slippery situations could very easily make the difference in driving home or walking home. You may want to forego the factory option and consider a more reliable aftermarket limited slip like the Detroit Tru-Trac. It is a gear driven limited slip and isn't subject to the wear of a clutch type limited slip. The Tru-Trac will not exhibit any of the quirks of a locker on pavement, it won't be noticed until it's needed. If you want the full traction a locker provides, you could use an ARB air locker. The cost is about twice that of a Tru-Trac (around 800 dollars including installation), but with a push of a button, it will lock both rear wheels together. Push the button again, and you've got a standard "open" differential.


"I have a question about CJ-7's, with a 350. Well...basically, I would like to know what years of the CJ-7's have the most solid axles/driveshafts. I am looking to pick one up that either has a 350 in it, or converting it myself. I am a big fan of the Chevy hardware, and once it's done, parts and help are quick and easy. My concern is how much power can one safely dump on the stock drivetrains of what years? (Assuming a 350 and aftermarket tranny)"

If you disregard the engines and transmissions of any CJ-7 (assuming they'll both be replaced) the differences are pretty minimal. Late model CJ-7's used an AMC model 20 axle with very weak two piece axle shafts. Once these axles are upgraded to aftermarket one piece units (about $350) the model 20 is just as reliable as Dana 44's found in early CJ-7's. Late model CJ-7's used the desirable Dana 300 transfer case, early CJ-7's used either a Dana 20 transfer case or the Quadratrac case, the best of the bunch being the Dana 300. None of the factory driveshafts are stout enough for continuous use with a high output 350. These can easily be replaced with aftermarket heavy duty driveshafts, but the limiting factor is still the U-joint size. How much power can the drivetrain handle? There's really no way to tell, it really depends on your driving habits. A stock 200 hp 350 can easily break expensive parts if driven aggressively. On the other hand, a well built 350 hp 350, driven conservatively, may not cause any damage. The important thing to remember is that even a stock 350 is sending much more horsepower and torque to the remainder of the drivetrain than the AMC engineers ever intended. For total reliability, every part of the drivetrain will need to be upgraded accordingly.


"I have a 1968 Jeepster Commando, with a 225 V6. I orignally had a T14a 3-speed, and I just swapped in TH400. The Jeep has 33x9.5's and 4.88 gears. The speedometer had been re-calibrated. I was turning 3500 rpm @ 70 mph. Now with the auto it is running about 3500 rpm at 65mph!! What gives? Is it the torque converter that is causing the increase in rpm at any given speed?"

You guessed it. It's the torque converter slippage that's causing the RPM increase. Modern automatic transmissions are capable of "locking" the torque converter to eliminate the slip at cruising speeds. Older automatics don't have this capability, which explains why there was a big difference in mileage numbers between manual trannies and autos in older vehicles.


"I have a 1987 Jeep Comanche, with a 2.5/4-speed manual. What's the cheapest, simplest, and best axle and t-case combo to convert my shortbed sportruck to 4-wheel drive? Thanks for any advice."

I don't normally suggest that anyone attempt to convert their two wheel drive to four wheel drive. It's simply much easier and usually far less expensive to sell your current vehicle and buy a similar 4wd. However, if you decide to attempt the conversion, there's no question that the easiest parts to use would be from another similar Comanche/Cherokee. You'll need a front axle with a ratio that matches the rear, an NP231 transfer case with a 21 spline input shaft, and another AX-5 transmission from a 4 cylinder/four wheel drive Cherokee or Comanche. Your existing transmission could be rebuilt to accept a transfer case, but it will likely be cheaper and easier to sell your two wheel drive transmission and buy another from a four wheel drive. You're rear driveshaft could be shortened and reused, but you will need to purchase a complete front driveshaft while you're shopping for the rest of the drivetrain parts.


"I have a 1997 Jeep TJ, with a 4.0/5-speed. Have a factory Dana 44/Trac Loc with 38,000 miles. Got stuck in deep snow and Trac Loc did not seem to work. Is this normal or is there a problem. Do I need to upgrade to air lockers? I do a lot of off-roading (4-5 times per month)."

In my opinion, the Trac-Loc option is a waste for anyone that regularly ventures off road. The problem with the Trac-Loc is exactly as you described, it doesn't work. It's effectiveness diminishes every time your Jeep is driven, the clutches simply wear out. Upgrading to an air locker, or any other mechanical locker would be a worthy upgrade that will greatly enhance off road performance.


"I have a 1995 wrangler, with a 2.5/manual. The front drive shaft is locked in no matter what position you have the transfer case in (4h,2h,4l). What do you think is causing this? The transfer case seems to shift o.k."

The front axle in your Jeep is a full time unit. In other words, if it had hubs, they would be constantly in the "locked" position. When you try and turn the front driveshaft by hand, you're trying to turn the front wheels as well.


"I have a 83 CJ7, with a 258,t-5,dana 300. Hope you've come accross something similar to this before cuz I can't figure it out. My CJ has a 4" suspension lift. Last summer I did an axle swap. I put in a dana 44 rear end. That was the only part of the drivetrain I touched, but now it is making a light growling noise when I put it in 4th or 5th gear. The first three gears don't seem to be making this noise. I actually lost 5th gear driving not too long ago. It seems to me like it would be the rear end. is there anything I should know about swapping in a 44? Is it just the gears in the rear end? I just can't locate where the noise is coming from. before the swap there was no noise. Can you help?"

The rear end may be the source of the noise. The fact that it gets louder in 4th or 5th gear (i.e. higher speeds) would suggest bad bearings in the rear end. Was the rear end rebuilt before installation or was it a salvaged part? Swapping in a different rear axle will not have anything to do with losing 5th gear though. Obviously, you're transmission is failing, and it is more likely the culprit.


"I have a 1994 Jeep YJ, with a 2.5 standard. My syncros are failing. Second gear is all most non functional and the rest are sure to follow. I've talked to a couple of shops for pricing and a few used parts stores. The shops said around $700 to start not knowing what else is wrong. Or I can go with a 12,000 mile tranie from a wrecked one that is still good. What would be my best deal to do? Second I have a noise that come out when I am slow rolling with first gear selected or reverse selected with the clutch pedal pushed down. I was told it could be a flat spot in a bearing assembly in the transfer case. Is that correct or is it another problem with the T-case along with the tranny?"

I'd shoot for the 12,000 mile used transmission. It will likely be much cheaper than rebuilding your current transmission, and less downtime. I wouldn't worry about the T-case yet, I'd bet the noise is gone after you replace the transmission. If it's not, then you can tear into the transfer case.


"I have a 1998 Wrangler Sport, with a 4.0 6-cyl. According to the invoice, it came with the 3-speed auto tranny in it. However, I have noticed that when gently accelerating, there are actually three changes in engine RPM during shifting instead of 2 as I would expect with a 3-speed. This has been verified by passengers so it's not just my sunbaked imagination at work. How do I get what appears to be a four speed tranny out of a three speed? Also, I have the factory soft top and half doors. I would like to get a hard top for it this winter and would like to know if I can use my half doors and soft windows with a hard top? Thanks for your advice and keep up the great column! "

The "bonus gear" you've noticed is actually the electronically controlled torque converter locking and unlocking. The torque converter essentially replaces the clutch in a manual transmission, the converter slips to allow the transmission to shift. Older automatic transmissions "slipped" all the time. The extra "shift" you're noticing is the converter switching from the normal "slip" to "locked", generally about a 300 rpm drop. If you'll recall, there used to be large differences in MPG numbers for manual transmissions versus comparable autos. Since virtually all newer automatic transmissions can lock the torque converter to eliminate slippage, mileage numbers with autos have nearly matched that of manuals.

Leon Rosser Jeep (http://www.thinkjeep.com) has a hard top that you can use with your factory half doors.


"I have a 1996 Cherokee, with a 4.0. I've noticed that the the front axle on the new Jeeps (96 and up) no longer have the vacuum operated axle disengage feature,why was this done? Will it hurt anything having the diffs spinning all the time? Also are there any kits available to stiffen the body to '97 specs ?"

Thankfully, the vacuum disconnect system is gone. The plastic lines were either ripped out by branches or rocks, or simply became brittle and broke. Since there isn't any significant force being applied to the front diff in 2WD, the extra wear on the gears is negligible.

Since the XJ is a unibody vehicle, I wouldn't expect to ever see any body stiffening components. Besides, a little body tweak can be beneficial off-road.


"I have a 1977 CJ5, with a inline 6/3-speed. Grant, I just bought my first Jeep and I am pretty sure it is mostly stock. I was wondering what kind of front and rear axles would be on it and what kind of transmission it is? Also, I plan on doing some off-roading, but mostly I will be using this Jeep as my main road transportation. What type of front and rear axles and transmission would you suggest? Thank you, Calvin"

Your transmission is a T150, transfer case a Dana 20, your rear axle is an AMC Model 20, and the front axle a Dana 30. Considering your intended use for your Jeep, there really isn't any need to go swapping very expensive drivetrain parts. The only inherent weakness is the two piece axleshafts that originally were installed in the rear axle. Considering the 20+ years your Jeep has been on the road, hopefully someone has already upgraded them to one piece units. If not, the conversion will run about $350 bucks. To check whether the axles have been upgraded, simply remove one of the rear tires. If there is a large nut on the end of the axle shaft, you still have the two piece units.


"I have a 1992 wrangler, with a 4.0/man..

What I really need to know is are the the stock axles strong enough?? I need to regear to 4.56 and would like to add ARB's. But do I do this to stock axles or should I spend the money more wisely on a Dana 44. I drive about 98% on road for now, but once geared right I plan on 50/50 +/-. I dont want to waste money on stock axles that wont last very long. Thanks, Ray."

As long as you intend to keep running the 4.0L engine, the stock axles should hold up fine.


"I have a 1979 CJ-7, with a 304/ T-18. I pieced together a Jeep with a 304, T-18, Dana 20 transfer, Corp 20 rear and a Dana 30 w/auto hubs up front. My problem is my T-case only turns the front meats in 4-Hi and not in 4-Low. Is it the axle or the T-case? Did I set something up wrong?"

The problem is with your transfer case, not the front axle. Take it to your local 4x4 shop for a proper diagnosis, but it should be a fairly inexpensive fix.


"Are there any possible upgrades/hop-ups for the 2.1 diesel?

Is this a good motor, and what are the major break-downs? What is parts availibilty like?"

About the only thing I know about your diesel is that it was a Renault design. With that in mind, I'd say performance parts are probably non-existent, and parts availability pretty scarce outside of dealerships.


"Grant, can you please tell me what fluid I need to put in my Borg-Warner T-5 tranny? So far I have been told to use Dexron II ATF (chilton's manual), non-detergent SAE 30 (local mechanic), and 80W90 (local parts store). Can you clear this up for me? I currently am using 80W90, but the tranny grinds going into 3rd and 4th and you can forget about downshifting into 3rd. It doesn't seem to be as bad before the Jeep warms up (if that helps)."

The T-5 uses ATF, most likely the grinding will stop after you switch back to the lighter oil. If not, it's time for a rebuild.


"I have a late 1989 Jeep Cherokee Limited 4.0 Auto. I need a replacement engine and am wondering if it is possible to put a diesel engine in instead. I live in Spain and since Cherokees have only recently started being imported here, no-one is prepared to attempt the job unless I can provide them with a complete detailed report of what is involved including part numbers and descriptions. Would a turbo-diesel fit? How would the cost compare with just fitting another 4.0 litre petrol engine? Any advice, recommendations or comments would be greatly appreciated. Thank you, Chris."

I wouldn't even consider the swap to a diesel. Jeep used a Renault built diesel engine in the mid 80's in the Cherokee's, but locating one of these engines and installing it would far outweigh any cost benefit of the diesel fuel. Rebuild your 4.0, it will be much simpler and less expensive, even in the long run.


"I am running 35" G-Hawgs with my little 4-banger, and I am way underpowered. What would be the 'easiest' and most economical engine swap. I use it on the beach and some light off road. And do you have any literature, books, previous issues that cover this."

A 258 straight six would be the most economical and easy swap. You can use all factory parts for the conversion. A swap to a V8 would require a stronger transmission.


"I am going to swap my 4 cyl.for an '82 258 ci. There is a 4-speed in my Jeep. What modifications if any can I expect? I hear it is a direct bolt in app."

Your four cylinder is a GM engine, the bellhousing will not work with the AMC six. You'll need a bellhousing from a 258/T5 combo for use with your T4 trans. You'll also need the factory engine mounts and radiator.


"I have a 1984 Jeep CJ7, with a 258/T5. I'm thinking of swapping out my T-5 for a more robust tranny. I've got a Dana 300 and would like to keep the swap as cheap as I can. Also, I'd like a synchro'd 1st gear. Is the Ford T-19 my best option? I believe it had a synchro 1st and although not as tall a ratio as the T-18 (6.32:1?) I think it would be enough (5.11:1?) I've heard the bell housing is a straight match but I would still need an adpater to the T-case. Does this sound right? Do input and output shafts match ok? Any idea on the cost of all this?"

The T-19 did have a synchro first with a 5.11 ratio, a significant improvement over the 4.03 first gear in your T-5. As you already know, your T-5 is marginal with your 258, transmission failure with the T-19 would be very unlikely. Your bellhousing is not a straight match to the T-19. You need a bellhousing from a 258/T-176 or T-150 combination. You'll also need a special pilot bearing available from Advance Adapters, and a new clutch. The transfer case adapter is costly due to the mismatched output of the T-19 and input of the Dana 300, it will set you back about $500.


"I am looking to either beef up the 4.2L I6 in my 1988 Jeep Wrangler, maybe go with a 8-cyl. I would like to know if there is an 8-cyl that will fit and adapt to my existing tranny or what type of increased and yet, practical performance can I get out of the 6?"

An AMC V8 will physically bolt up to your Peugeot 5 speed, but I really don't recommend doing it. If you want a V8, plan on using a different transmission, the Peugeot is not up to the task. Probably the best modification for your 258 is the Mopar EFI kit. The kit costs about $2000, but that's much less than you'd spend on a new V8 and transmission. Power will come up dramatically with the kit, expect about a 50 horse increase. The best part of the kit is probably the fact that you can drop kick your Carter carb, you'll never have to fiddle with it again. Obviously driveability is another huge benefit of the EFI kit.


"I am interested in installing a NV4500 transmission into my TJ. I have two choices: An NV241HD, or Atlas from Advanced adapters. I Have two concerns: Reliability and over all length of the new assemblys. I would be installing an output shaft conversion kit along with a 4to1 gear set in the 241. I want to remove the clearance reducing transmission crossmember spacers that were installed as part of my teraflex suspension. The cost factor isn't too much of a concern, but the Atlas would be cheaper. Which configuration do see to be the absolute best?"

I'd use the Atlas case. The rear driveshaft length will be critical in your TJ, particularly if you want to remove the crossmember spacers. The Atlas is a couple inches shorter overall allowing a longer driveshaft than the 241. The Atlas also benefits from a gear drive design-no chain related grief. The only downside I could see is the 3.5:1 low versus the aftermarket 4:1 gearsets available for the 241. However, if you use an NV4500 with a 6.34 first gear, 3.5:1 Atlas case, and 4.56 gearsets in the axles, you still end up with a plenty low final drive ratio of 101:1.


"I want to change the transmission in my 1957 CJ5 to a T98. What do I need , and where can I find one?"

All you need is the OEM T98 transmission and four cylinder bellhousing (your T90 bellhousing will not fit the T98). Unfortunately, finding one is much easier said than done. You might try an add in our classifieds. The T98 is about 3" longer than the T90, new driveshafts will be necessary.


"I am currently rebuilding my 1979 CJ7, frame up. I have a million questions but for now I would like to kick up the horse power of my 304. I don't want to go crazy with it, so what would you suggest?"

I'd suggest an aftermarket dual plane manifold, stock compression pistons, a mild performance cam (with matching valve springs) such as the Edelbrock Performer or the 252H or 260H series cams from Competition Cams, and dual exhaust. This should wake up your 304 at higher rev's (3000+), without any loss in low end torque.


"After driving at highway speeds for 30 minutes or so the temp gauge goes all the way toward hot. I have replaced the thermostat, water pump, temp. sending unit, and fan clutch. When I stop I don't hear coolant running out into the recovery tank. Is it really running hot or do I have a bad gauge? Any suggestions greatly appreciated."

It's possible that your radiator is clogged to the point that it cannot cool effectively. A professional cleaning may be a good idea regardless and is fairly inexpensive. The factory temp gauge on CJ's is vague at best, you might also consider installing an aftermarket temp gauge to find out how hot your engine really is.


"I was wondering if it is an economical or even a smart idea to try a V-8 swap in my 1990 YJ? What kind of mods would I have to perform i.e. gears,tranny, transfer? Or, could I keep what I have I am running 33s' what about the gears? Thank you very much."

Economical? Nope. Smart? Probably not. If you really love your YJ and have no plans to sell it than it's not so bad to drop the bucks for a V8. Be sure to check local emissions laws before you start the project though. If you intend to install a stock or only mildly modified V8, then all you need to replace is your transmission, your transfer case and axles will be fine.


"My CJ-7's T-5 is trash - gee, there is a surprise. I also play with Mustangs, and I notice there are at least three bolt in replacements for the Ford T-5 in the Mustang. Do any of these companies such as Tremec, Borg-Warner or Richmond make a world class T-5 for 4WD's. Is there a vast difference from the car type T-5 that precludes one of them from easily tooling up a 4WD T-5. There is a huge market of ruined T-5's in Jeeps waiting for a bolt in stronger trans. How about taking the guts from one of these stronger trannys and putting them in the Jeep T-5 case? Is this possible. I really don't want to install an NV. What I would really like is a 4WD version of the Richmond 6-Speed, now there is the best of all worlds, strength, overdrive and a really low first gear. Please help."

The trick with installing any of the transmissions you mentioned isn't adapting it to the engine, it's mounting the transfer case to the back of one. It can and has been done with the Richmond transmissions, but the cost of an NV4500 would likely be less. The Richmond six speed itself would cost more than a complete NV4500 with adapters and it's 4:1 first is not even close to the 5.61 or 6.34 1st of the NV4500. New Venture will be producing a 6 speed very soon and it should prove to be much easier and less expensive than the Richmond.


"I have a 1978 Jeep J20, with a 360/auto. When I shift into gear and step on the gas the engine will turn up, but no power will be delivered to the wheels, then it will take off just like nothing happened. After you drive it for 20 min or so it acts perfectly normal. Any ideas?"

If the fluid level in the transmission is correct then it's probably time to take your Jeep to a trans shop for a rebuild.


"I have a factory Track-lock rear on my 1992 Jeep YJ, but I would like to lock my front axle. It sounds as though I cant use an inexpensive EZ-locker or something similar because the vacume system only locks and unlocks the right side axle. So, correct me if im wrong, a EZ-locker will spin my front driveshaft (via the left axle) causing unwanted fricton and weird steering on 2WD dry pavement. An ARB would work, but can I convert my automatic hubs to manual with some kit and ditch the dumb vacume hoses? Or would this kit and the EZ-locker be more costly than simply buying an ARB?"

You're correct about the problems of installing a locker in a YJ front end. Unfortunately, there isn't any easy way to convert this axle to a manual hub setup, doing so would require completely rebuilding the axle using custom components. Installing an air locker is the way to go.


"Is it possible to install hubs to a Wrangler front axle?. Perhaps this question may sound without sense. But the thing is that Wranglers where sold in my country until 1994, and I haven't seen a single one featuring them. When I asked for information I was told that the tips of those axles are different from those of CJ's and it is not possible to install hubs to them. Are Wranglers designed to keep spinning the transfer case due to front wheel spin? I'm not a 4WD expert. I hope this could answer a similar question about Cherokees. I'm also interested in air lockers."

Unfortunately the Wrangler and Cherokee front axles cannot easily be converted for use with manual hubs. The modifications are extensive and best left to a custom axle shop. Since the Wrangler/Cherokee front axle uses an "open" (i.e. no limited slip device or locker) type differential, the front driveshaft is not directly driven. The front driveshaft may still turn, but "slip" is allowed via the disconnected passenger side axle. The front driveshaft would only be directly driven if a locker was installed in the front axle. Since an air locker can essentially be turned on or off, you could avoid the nuisance and wear of the front driveshaft constantly being driven.


"Last spring I had my aging 258 rebuilt (1983 Jeep CJ7, with a 4.2/T-5) by an area machine shop. It was bored .030 over and I had them install a mild performance cam. When I reinstalled the engine I added a Borla header, a weber carb, and a Jacobs Omni Pack. The problem is that the engine now has noticeably less power than before. All the modifications I made are standard performance mods. I Asked the machine shop what the compression ratio was and they said 8.2:1. The Mopar jeep engine book gives 8.0:1 in the 4.2 section and 8.6:1(for the 4.2) in the 4.0 section. An old road test from another magazine said 9.1:1. Do you have any idea what the correct compression ratio is?"

My book says the stock compression ratio was 8:1. This may have changed depending on the pistons used in the rebuild, head gasket thickness, and whether or not any material was removed from the head or block to correct for any warped condition.


"My '84 CJ has a 4.0 liter from a '93 Cherokee, 4.11's and lockers front and rear, and the stock three speed automatic transmission. What can I do to get more torque to my 33x12.50's without having to go into the gears or the engine?"

If you eliminate modifications to the engine and the gearing behind it, you eliminate the ability to produce more torque. You'll either have to make modifications to the engine to produce more of it, or swap to lower gearsets to take better advantage of the torque the engine does produce.


"I am interested in raising my YJ about 3" and going to 31" BFG AT's. This will mean a trade off height with pickup. Is there a relatively simple way to get another 50 horses out of my 4.0L?"

Fifty horsepower would be a huge increase for your 4.0L. The only way to gain that kind of power without rebuilding the engine would be with an aftermarket supercharger, and that's not necessarily simple or cheap. You might look at replacing the axle gears with a lower ratio set to make up for the larger tires rather than trying to increase the power of the engine to overcome the too tall gearing.


"I want to swap a 304 v-8 in place of the stock 258 in my '89 Wrangler. Will it bolt up to the 5 speed transmission? Will the transmission hold up to the 8 cylinder? Will I have to use a different clutch/flywheel and motor mounts?"

The 304 will bolt up to your Peugeot transmission, but I wouldn't expect it to last more than a few months. You'll need to use a more sturdy transmission. When you buy the 304, be sure to buy one with a manual transmission flywheel still attached. Not only are you getting the flywheel you need, but it tells you the crankshaft is drilled for a pilot bearing, some car V8's with auto transmissions weren't. Contact Advance Adapters for your motor mounts.


"You've said that a 904 was used on a 4cyl & the 999 on a 6cyl. I was told the the other way around. How can you tell from the outside which is which? I have a Dana 300 which goes into 4wd easy, but does not want to come out easy, a problem maybe? Does any 727 or Turbo 400 fit the Dana 300 directly?"

The TF904 was used on 4 cylinder CJ's and early 2.8 V6 XJ's. The TF999 was used on both six and eight cylinder CJ's. The 999 and 904 shared the same case, distinguishing between the two without knowing the transmission's origin may be difficult. The only external difference I know of is the 999 used a larger torque converter. The 999 also had a lower first gear than the 904. The TF727 and TH400 transmissions were both used with the Dana 20 transfer case, the TH400 was also used with the Borg-Warner Quadra-Trac transfer case, neither were ever used with the Jeep version of the Dana 300. Installing either would require a transfer case adapter.


"I am trying to figure what would be the cheapest way to swap an auto for my T-4 (1983 CJ-7, with a 4.2/manual, 300 T-case). I thought my best bet may be to find a CJ-7 with an auto from the factory, but I'm not sure what kind they were or if they came with a Dana 300 T case. Any thoughts greatly appreciated."

Look for a Torqueflite 999 out of any six cylinder equipped '80 up CJ. It was used with the Dana 300 case and would be the easiest swap. You might also consider a floor shifter for the new auto rather than trying to hook up the factory column shift linkage.


"Are there aftermarket companies that make a carburetor that will replace my stock 'California Legal' 2-barrel and how would I contact them for technical information."

I don't know of any CA legal aftermarket carbs, but Turbo City (www.turbocity.com) can set you up with a CA legal EFI system.


"I own a 1987 Jeep wrangler with a 258ci 6cyl. I have a 5-spd trans. which is blown, 3rd gear grinds and wont hold and reverse doesnt exist, you can put it in reverse without the clutch and nothing happens and the tranny sounds like it has a lot of metal rolling around in it even at idle. I think it is the infamous 'Peugeot' tranny?

I have found a trans from a '95 YJ it is an 'AX15' 5spd w/clutch and only 920 miles.

I am waiting to see if it is still available, but I am wondering if this will bolt up to my Jeep or will there be any modification ? Can you shed some light?"

I replaced a Peugeot tranny with an AX-15 almost two years ago and wrote an article on the conversion. It can be seen at http://www.dirtroad.com/tranny.htm. The only potential problem I can see with your '87 is that it may be equipped with the NP207 transfer case. If there isn't a 23 spline input shaft available for the 207, you'll have to swap the case for a later model NP231.


"I have a 1967 Jeep CJ5, with a 225 V6 / T86 3spd. Engine is shot, but rebuildable. What GM V6's bolt up to bell housing? What is availability of cams and intakes for the 225? How much is interchangable with the 231 V6? Any V6 that you would recommend? Thanks..."

Competition Cams lists three different cams and related valve train parts for your 225. A quick call to Summit Racing (www.summitracing.com) and you should be able to locate an intake without difficulty. Considering the performance parts available for the 225, you're better off trying to squeeze some more power out of it than spending the money on another complete V6 and the necessary swap parts to make it fit.


"I have a 1997 TJ, with a 2.5/std with a factory trac-loc rear. For ice and snow and everyday driving, most seem to recommend the Tru-Trac for the front. I can live with the higher price if that is correct, but can you tell me how difficult the installation is for a backyard mechanic? Any tips? Thanks!"

The Tru-Trac is a gear type limited slip and does not use clutches like the factory Trac-Loc. The performance of each when new is more or less equal. The Trac-Loc's performance will quickly diminish as the clutches wear, making the Tru-Trac a better choice in the long term. As for the installation, you will have to remove the gears and reset them. This isn't impossible for the backyard mechanic, but I don't recommend it either. Most shops charge less than $200 for a professional installation. Considering the work involved, that's a bargain.


"I have been given a completely rebuilt Chevy 292 straight 6 and would like to swap out my sick 304. Possible? What adapters? Appreciate any and all help/hints."

I must admit it's not often I get a question regarding the installation of a smaller than stock engine. The straight 6 would probably fit, but the hassle of installing it would far outweigh what little money you'd save. You might be able to purchase a new bellhousing (around $350) to adapt the engine to your current transmission. If not, you'll have to use the Chevy bellhousing and transmission that the engine was originally equipped with and adapt that combo to your transfer case. With the longer straight 6 and transmission swap, you'll probably need to relocate the transfer case and have new driveshafts custom made. You'll also need a new exhaust and you'll be completely on your own as far as fabricating motor mounts. I think the best bet is to spare yourself a lot of headaches, sell the 292, and use the cash toward a 304 rebuild.


"I recently purchased a 1982 Jeep CJ7, with a 258 4 speed and it is in excellent shape. Now I want to install some lockers, however I don't know how to find out what axles or gears are in the Jeep. Can you help me?"

Your '82 has an AMC Model 20 rear and Dana 30 front axle. The Model 20 originally had a failure prone two piece axle assembly. If your Jeep hasn't already been upgraded to one piece axle shafts, you should do so before installing the lockers.

The easiest way to determine your gear ratio is to check the tag that's bolted to the front differential cover. On the tag you should see some numbering such as 3.54 or 3.73, either of those numbers would indicate the stock axle ratio. To verify this (your gears could've been changed) jack up the rear axle and support it with jack stands. With the transmission in neutral, rotate the rear driveshaft by hand. Count the number of driveshaft revolutions required for one revolution of the tire. If the driveshaft turns approximately 3 1/2 times, you have a 3.54 ratio. It's helpful to use a grease pencil or chalk to make a reference point on both the tire and driveshaft.


"I noticed that you addressed the parts cost of performing a V8 conversion, but I would like to know if you believe most Jeep specialists are capable of the conversions, and how much their labor might be. On a related, but separate model topic, is it feasible to put a V8 in the earlier Ford Explorers (1991)?"

I think there are tons of shops with talented mechanics capable of a Jeep V8 conversion. The problem is with rates of $50 or more per hour on a job that takes on average about 40 hours to complete, very few Jeep owners are willing to pay someone else for the work. I'd wager 99% of Jeep engine swaps are done in the owners garage.

A V8 swap in an early explorer/ranger can be done relatively easily. Advance Adapters and probably James Duff can set you up with the necessary swap parts.


"I'd like a Chevy V8 and auto transmission in my Jeep. Right now, the frame is bare and ready to re-assemble. My question is, is it possible to bolt on the entire running gear from an older full size Blazer to my CJ7 frame? Would the axles stick out too far with proper offset rims? I could buy an adapter to fit my Dana 300 transfer case but they are very expensive in Canada!! (40% exchange, shipping, taxes, duties)"

You could use the Chevy engine, trans, and transfer case, but not the Chevy axles. They'll stick out way too far. I'd suggest popping for the Dana 300 adapter anyway. If you kept the stock transfer case, you could leave it in it's existing location and totally avoid shift linkage bending and having custom driveshafts built. The yokes on the Chevy transfer case and the Jeep axles won't match either. If you can't find the right yoke for the transfer case you may have to run two different size U-joints on the same driveshaft to get the whole thing to work. That driveshaft will drive you nuts with vibration not to mention possible damage to the case and axle.


"My '82 CJ7 258 auto stalls out when I stop in drive. I recently had the carb overhauled, new air filter, wires, PCV and plugs. When I got it back from the shop it ran ok for a week or two. My mechanic keeps adjusted the carb (idle adjust) and it's ok for another week or so. Any ideas?? When it stalls it really dies quickly, no stumble or anything. The tach drops to zero instantly."

Assuming the carb overhaul was done properly, you might want to check fuel pressure. You may have a clogged filter or weak pump.


"I am in the process of swapping a SB 305 Rat motor and TH350 tranny into my CJ. The original consisted of a 258 inline with a T5 manual tranny.

I'm trying to wire the ignition circuit and am questioning how to wire the new HEI distributor?"

The Chevy HEI distributor is super easy to hook up. Take the old "+" coil wire and hook it up to the "BAT" terminal on the distributor (it's the terminal closest to the firewall, the other is for the tach). There is another plug that originates from the ignition module inside the distributor that also plugs into the cap, it only goes in one way. That's all there is to it.


"I am currently in the process of placing a CJ5 body on a CJ7 frame, so I am able to place a decent size engine like a small block Chevy and was wondering what tranny and how to bend the transfer case stick so I am still able to select 4low, 4 high and 2 high."

There is no need to go to the extreme of swapping bodies to install a V8. A small block chevy (and any other small block for that matter) will fit in a CJ-7 without problems. If your Jeep originally had a GM 151 four cylinder engine, then the chevy V8 will bolt directly to the 904 transmission. However, if you want the 904 to last, you should keep engine modifications to a bare minimum. If you originally had a 6 cylinder, then you will need to purchase an adapter plate for your 999 transmission. Neither of these swaps would require relocating the transfer case; bending it's linkage won't be necessary.


"I would like to know if the AMC 390 will bolt up to my TH400. The Jeep had a factory 304 so I know I could go back with that block or 360. How about a Dodge 340. I know what to look for to find a 340 in but what did the 390 come in besides the AMX."

I wouldn't even mess with the Dodge 340 when there are so many easily swappable AMC's out there. Your 258 has the same bellhousing pattern as the AMC V8's. You'll need new motor mounts and a fan shroud, and possibly a new radiator depending on the size/output of the engine you're using. The 390's were in '68-70 AMC Ambassadors, Javelin's, and the AMX, but any of the AMC V8's (290-401) are bolt-ins.


"I recently installed a new Cooper City engine and added a 400CFM Weber, Borla headers and a Jacobs Omni Pak. I figured this would get rid of the ping. It didn't. Now I am being told that a new distributer, that does not run off all the 300 vacuum lines on the engine, might solve the problem. Two mechanics have given it their best shot, but the ping remains. If I accelerate hard, it goes fine, but hold a constant speed down the interstate and you hear pings. It is making me crazy. Got any suggestions?"

The easy fixes are to retard the timing a degree or two, or simply run 91 or 92 octane gas. Your Jeep is also equipped with a knock sensor that is supposed to automatically retard the timing in the event the engine starts "pinging". You'll need to take your Jeep to the dealer or obtain a good manual to determine whether the sensor is still functioning properly.


"For the second time in the life of this Jeep, the syncro gears seem to be bad, grinding into second gear. I would like to put in a 5-speed, but am concerned about durability. In reading the archives it appears newer Jeep 5-speeds won't work. I would perfer not to spend to much on adapters."

Unfortunately, installing a reliable 5 speed is not cheap in a CJ. The only one to seriously consider in your application would be the NV4500. The T5 and newer YJ AX-5's are much too small for a V8. The AX-15 from a 4.0 YJ should work, but if you're going to go through the expense and labor of a transmission swap you might as well go with the plenty strong NV4500. The conversion will be a little over $2000 including the transmission.


"This Wrangler belongs to my friend, so I don't know all the details. Anyway, the other day he was driving home from the store, when he went for 5th gear he noticed there was no resistance and then he realized there was no 5th gear (when he lets the clutch out the engine just rev's as if in neutral. He did not notice any problems up till that point. The Jeep is 100% stock with 75,000+ miles (mostly highway). He is not the type that beats on his Wrangler. He is wondering if this is a common failure and what the exact problem could be? The tranny is fine except for no 5th gear. Thanks."

The Aisin AX-5 is not a real stout transmission, but normally it's fine with the 4 cylinder. I don't think your friends exact problem is by any means common, but it's not hard to believe either. If I had to guess I'd say it's a shifter fork, (i.e. replace the shifter). It should still be taken to a transmission shop if your friend isn't comfortable messing with it. Be leary of a shop that says it needs a total overhaul though, check several shops before letting them tear into the Jeep. Once they've got the transmission pulled, you're at their mercy.


"Since the newer ZJs (95+) now have 4-wheel disc-brakes, would it be feasible (or even possible) to convert my '93 ZJ's rear drums to discs using parts from a donor late-model ZJ with rear discs? If so, will the parts swap without mods to my axle or drivetrain? If this can't be done, is there an aftermarket disc-conversion kit for the ZJ? Finally, would the difference in stopping distance/time be significant enough to warrant the conversion? Thanks in advance for your help!"

I'd guess (I haven't done it) the conversion would be a bolt on as long as the donor vehicle used a Dana 35 and not a 44. You would probably need the donor's axle shafts as well. If you have the factory ABS, I'm not sure if the new discs would be compatible. Contact Stainless Steel Brakes Corp (800-448-7722). They manufacture bolt-on disc brake kits and should be able to shed some more light on both the conversion and any ABS conflicts.


"Grant, I have a mildly built 360 in my CJ7. I presently have a T-18. I want to change to an auto. I have a 904 from an '83 CJ8. I have been told the 904 will not hold up. I'm not going to do any mud racing, mainly trails. Whats your opinion and what could I do to beef up the trans for heavy duty use? Thanks.

The biggest engine Jeep ever used with the 904 was the 2.8 V6 in early cherokees. I'm afraid your 360 would eat up the 904 pronto. You could use an AMC TH400, or even adapt an overdrive GM TH700R4 to your AMC engine and transfer case.


"When the engine is cold, I'm having problems with stalling and stumbling. I have to keep the engine revving in order to keep the engine from stalling. I also have problems with the engine running on after I shut the ignition off. I'm fairly certain the culprit is my carburator. I've tried carburator cleaner and rebuilding, with no luck. Do you know of a 'good' replacement or any manuals on how to fix these things?"

If your Carter still won't run right after a rebuild, the best swap may be to a simple aftermarket throttle body type injection setup. It won't cost much more than a new carb and it will solve your induction problems for good. As a band-aid in the meantime, you should be able to stop your engine run on by using high octane gas (assuming your ignition timing is correct).


"In the process of rebuilding and 'building up' the 258 out of my 1978 J-10 pickup. Looking for performance parts for it, and are coming up short handed on the pistons and valves. Any leads to such animals, without having them custom made? Have a Offenhauser intake, holley 390 carb, and clifford split hedders. It is being built by a pro, but he has never done this engine before and wants to talk with someone that has done it before. Needs technical garb on clearances and so forth. I know, should have gone for the V8 swap, but this is far more interesting!"

Contact Summit Racing (www.summitracing.com) or Clifford Performance for performance pistons and valves.

For clearance and other general rebuild related specs, get your hands on the "Mopar Jeep Engines" book. It should be available at your Jeep dealer (PN 5249586) for 25 bucks. If you have problems finding it locally, you can order it from Leon Rosser Jeep (www.thinkjeep.com).


"I was wondering if you could give me some thoughts on what would be a good tranny and t-case swap for my '71 CJ5. I currently have 225 V6, T14 tranny, and a Dana 18 t-case, and 32" tires.

I was thinking about Advance Adapters World Class T4 or T5, which would be better? I would like better highway speed w/out having to mess w/ my Dana 44 rear end. I've been told that putting a NV4500 would creat alot of driveshaft problems, would the benifits of this tranny outweigh the problems?

What problems would I run into in either keeping my Dana 18 or replacing it. I've heard alot of good hype on the Dana 300, could this be a good choice? Do you have any other suggestions.

I plan to keep the 225 V6, so will I be able to keep the bell housing?"

You can keep your existing transmission and transfer case and add a Saturn Overdrive. The overdrive unit is essentially a two speed transmission. It bolts on to the back of the case through the inspection cover, it is fully synchronized, and it provides a 25% overdrive when engaged. This unit will give you the option of 6 forward gears and 2 reverse. The overdrive unit does not affect the driveshafts, so no modifications would be needed to add the unit, it's simply a bolt on. Advance Adapters sells the overdrive for about a grand, much less than you'd spend on a trans and case swap, not to mention a whole lot less labor.


"I own a 94 Wrangler. I'm wanting to swap a 350 chevy for my 4 cylinder. What are the pros and cons for this swap? Will I have to swap the front suspension? Will the tranny hold up? Will a 2.5 lift be high enough? And what kind of kits are available? Any info would be greatly appreciated."

Your existing transmission will not hold up with a 350. Even a stock 350 produces twice the torque of your 4 cylinder. There is no need to install a lift kit or any other suspension modifications in order to install the V8.

The pros are pretty obvious, you'll have tons of power. The list of cons is unfortunately much longer. The biggest deterrent to an engine swap as I see it is the cost. Expect cost to be a minimum of $2000 for a used engine and transmission and all the necessary adapters and miscellaneous parts to hook it up. Unless you're really cutting corners, the total cost will likely be $3000 plus. Don't get me wrong, if you can afford it, it's worth it. It's not always practical though. Check out Advance Adapters (www.advanceadapters.com) and JB Conversions (www.ng.netgate.net/~tc/jbconversions) for more info.


"I have a 1948 Willys CJ2a which someone has already installed a Buick V6 with T86 transmission. I know that the T86 was one of the stock transmissions Jeep offered for the V6. My axle's are original. I plan to rebuild the engine and transmission. What is your opinion as the the reliability of this setup for moderate off-road use as well as around town? Assume that I will have larger than stock tires. Should I consider a truck 4-speed transmission? I worry about this conversion due to the cost of adapters and all the positioning/alignment headaches. Finally, can you recommend a radiator for this setup that will fit?"

The T86 wasn't the most stout transmission Jeep ever used, but I don't think it would be failure prone with a V6. Unless you just really wanted a "granny low" first gear transmission, I'd suggest saving yourself a ton of money and sleepless nights and keep your T86. The rest of your drivetrain should hold up well too. The stock axles aren't the most stout setup, but the cost of custom built units would probably far exceed the actual benefit. In my opinion you've got a very nice/practical setup for "moderate" off-road use.

I don't know of any drop in replacement radiator for your Jeep, probably you're best bet is to have your local radiator shop custom build one.



Dirt Road Magazine is sponsored by Turner 4WD Parts Co.