Yeah, with one wheel on the ground the number of wheel revs it takes to make a full driveshaft rev would be either 7 (3.55 gears) or 8 (4.10 gears). Should be pretty easy to tell the difference. They actually come with a tag on one of the diff cover bolts stamped with the ratio, but more often than not the tag gets left off and lost at some point when someone does a diff fluid change.

Like I posted earlier, to have 4.10 gears with a V6 auto, someone would have to have swapped them. Most people doing that wouldn't spend the kind of money required ($400-$500) to upgrade to 4.10 - it is much more common for people to go to the next step and install 4.56 gears.

Of course someone could always have installed the axles from a 4-banger automatic - like the one I got...

 

Hi John, how did you know what lock-up type setup your trans had? Is it a model year thing or is there some way to identify what I have. Mine is an 88 90 deg trans. Also it would be nice to know for sure what gears you have for comparison, I still have a ways to go before mine hits the road. I have 410s, appears to be stock. BTY, did you use a driveline in the front with a constant velocity joint at the t/c end? I thought you said you used one from a s10.

 

I hooked up the lockup wire to the trans to find out which one I had. There are several different pressure switches inside the trans, they changed over the years. Some ground internally, some you need to ground terminal D. Some will lockup right away, so you will need a way to control the voltage going to the trans. Mine only locks up in fourth, and I had to ground the D terminal, so I won't need to use a controller. You could run a 12 volt wire to the trans with a toggle switch (but don't mount it yet) take it for a drive and see when it locks up. You will probably need to control the lockup, I think the models that lockup in fourth were only produced up until 1985. But , try it, you might get lucky. You could run a hot wire right to the trans for testing, but if it locks up too soon, you'll never get it unlocked!!!

My front driveshaft is out of an S-10 Blazer. There are U-joints on each end. The splined slip joint is near the diif end. The Blazer shaft fit the TC and the diff couplers with no mods, bolted right in. I am anxious to see you get her rolling!!!1

Hope this helps,
John

 

In a V6 Auto? Got the tag on the diff cover bolt that says 410? I'd like to see that.

You don't have to take my word for it, look it up for yourself. If you can find a source that says there was a factory option to get 4.10 gears in a V6 Automatic in 1986, then let me know - I'd love to add it to my list of Jeep info links. Every source I've found says that 3.73 gears were an option - the ONLY option - with the V6/auto drivetrain - and you only got them by ordering the towing package. But not 4.10 gears, not factory stock, there was no such animal.

 

I guess I have the only one in captivity! The diff tag is intact, but too poor to read, so I checked the old fashioned way. I figure the early days of the cherokee were hit or miss due to the troubled times of AMC and all the mix and matching of parts and manufactures.

 

Actually AMC wasn't in bad shape when the XJ was first produced. They were owned by Renault, which was still a pretty major european manufacturer at the time. Did you know the XJ was the first vehicle to be fully designed and crash tested through computer simulation before the first one was ever actually built? Renault owned one of the only half dozen or so Cray SuperComputers in existence at the time, and it was used to design and test the XJ's moncoque "Uniframe" body structure.

I still propose the theory that somebody swapped some aftermarket gears - or even complete axles from a 2.5L auto - into it. BUT, I can tell you how to find out 100% for sure. Take your VIN down to the Chrysler dealer (or you can email Chrysler from their website - I have the link somewhere on my computer at home) and have them run it for you. They'll be able to provide you a build sheet that lists EVERYTHING you could ever want to know about the vehicle - including the axles.

BTW, that's really weird about the diff tag being unreadable. Every one I've seen is punch-stamped from the back - meaning they are actually RAISED numbers - rather than being punched or engraved into the front surface of the metal. They were done that way specifically to make it harder for the numbers to be obliterated. I can't think of any way to make one unreadable - other than pounding it flat with a hammer. I also can't think of any reason anyone would want to do that - unless maybe they swapped the gears and wanted "wipe it clean" to re-stamp the tag with the new ratio.

Just out of curiousity, I was wondering what makes you so sure the gears are stock pieces anyway? You said they "appear" to be stock, but I've never seen or heard of any way to be able to tell the difference between a stock and and aftermarket ring & pinion just by their appearance...

 

I give! This is my first Jeep, so I don't pretend to know squat about them. I am a Ford guy and I just assumed that AMC/Jeep/Renault/Mopar didn't always follow the exact letter of the build book/sheet. I know that it was very comon to find different parts in a car that shouldn't have been, but was anyway because they ran out of the "stock" part and subbed. And yes I took the tag off and it was too rusted to read on the back as well. What I ment by "appears to be stock" was that the rest of the Jeep appears to be unmloested and fairly clean and "stock" unlike so many I hav seen. That said, I really don't care weather it was "factory" or not cause it is WAY past that now!

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Hi John, about the front drive line, I was concerned that going with the non c/v shaft would cause vibration. The c/v shaft I have wont bolt up to the yoke. I guess I will have to see if a 231j yoke will fit on my 231c. You may not have a problem due to the fact that I lifted mine 3in and yours is probably 1in lower than stock.

 

LOL! Sorry, but this one I'm working on is my SIXTH Jeep and my fifth/XJ Cherokee. I have 3 XJs and one WJ (2001 Grand Cherokee) in my driveway right now. I'm a bit of a fanatic about the XJ and I'm the type who LOVES trivia - so naturally I'm a treasure trove of useless trivial information about them. I don't claim to know everything about them, far from it, but I do know a good bit about them, and I've also gathered a lot of links where I can find out just about anything I don't already know about them online.

As for the rest of the Jeep lineup (TJs, YJs, ZJs, WJs, LJs, KJs, and JKs) I know just about as much as your average Jeeper - pretty much the basics. Its only XJs that I've spent the time online - and on the flat of my back in the driveway - to learn everything I can about them over the last 5 years...

Fords? You could no doubt put me to shame there. About the only Fords I know more than the bare minimum about are the 83-93 F250/F350 IDI diesels (6.9 and pre-PowerStroke 7.3). I've learned a fair amount about them because I own an 86 and have done a ZF5 swap and some other customizing/tweaking on it over the last 3 years...

 

Negative on the diff tags, it was common- only the LS friction modifier was raised in europe...



I'm also crazy about my Diesel XJ. But the engineers haven't done a good job at all.
had to learn about the "thing" in the last 2 years. I bet I know a bit more than average about the Diesel engine.
I would be happy if I could ask you about the body mods- I don't like the Jeep sites...

 

Must be a European Jeep thing - those don't look like the tags I've seen. I don't even see any recognizeable gear ratio info on those. Actually they look more like what we call a BOM (Bill Of Materials) number tag...


You probably do - but most of it would pertain to the 2.5L - which was never offered in the US. I guess I should have qualified my earlier statements. I know quite a bit about the US-spec XJs. I know very little about the European OR Chinese variants.

You mean things like body armor, rocker (door sill) protection, heavier bumpers, grille guards, tail light protection - that kind of stuff?