Before you ask a gearing question - look here

This thread will become the depository of regearing info for ALL to read. The same questions get asked constantly and HOPEFULLY this thread will cut down on that somewhat. I will be gleaning the best of the best info that has been posted on . In order to keep this thread clean and to the point, it will be locked. If you want to provide info for the thread, either PM or email it to me or send me a thread link.

This won't happen overnight but hopefully we can make it worthwhile.

Before you start thinking of regearing, you really need to know what type of axles you have under your rig. Here is a link to a chart that should help you with determining that. In the future, once permission has been given, that image will automatically show up here. Also a listing of the most probable axles you would have, identified by year and model will included.

http://www.coloradok5.com/axleguide.shtml


Front Axles






used 84-99 Dana 30 high pinion (reverse cut)Axles from 84-90 appear to have the vacuum disconnect. (could use some pix here)



Somewhere in 92 they changed to no vacuum diconnect
ABS was used from 89-95
95+ axles have the axles with stronger 5-297x ujoints while the earlier ones have 5-260x joints
(could use pix and how to tell the difference in them, ie ujoint diameters)

Starting in 2000 the Dana 30 low pinion (standard cut) appeared.

A common upgrade to the early disco axles is to replace the shafts with
the later larger ujoint versions. Mod's must be made to change the seals.
There are several good articles out there on this, and also IIRD a manufacturer
makes a kit for this as well.

Rear Axles



There were 5 major type of rear axles used on XJ from 84 forward. A common misconception is that the C in Dana 35C means c-clip. This is incorrect, It simply means custom.

The Dana35 non-C clip axles were used from 84-89 and were 27 spline.
They had a 1.18" shaft diameter and a 7.58" ring gear.

The Dana35 C clip axles had similar specs and were used from 90-01

Note: While you may find specs that give a single axle tube diameter for the
D35, I have personally seen 4 different tube diameters used.

Note: If you have ABS, you do not have the Chrysler 8.25, you have the Dana35.

The Chrysler 8.25 used from 91-96 had 27 spline, 1.17" diameter shafts, 8.25" ring gear, 3" axle tube. Some vehicles have been found that had the 29 spline that were built in 96.

The Chrysler 8.25 used from 97-01 had 29 spline, 1.21" diameter shafts, 8.25" ring gear, 3" axle tube

Now for the famous Dana 44 non c-clip - 30 spline, 1.31" diameter shafts, 8.5" ring gear, 2.75" axle tube. It was available from 87-89 on various versions of XJ's, mainly ones with tow packages. They seem to be much more common on the 89's than other years.


GEARING
Here is a rough guideline to what gears you MIGHT have.

3.07 - These were used with 4.0L engine when equiped with a manual transmission
3.31 - only available on older (pre87?) 2 door XJs with "Fuel Economy" package
3.55 - Commonly used with 4.0L engine & automatic transmission
3.73 - Commonly found in XJs with the towing package
4.10 - Mostly found with 2.5L engine usually, and older XJs with the "Off-Highway Vehicle" package.
4.56 - While this has been found to be a valid setup on the XJ, no one claims to ever have actually laid eyes on one. A few...a friend's brother-in-law sightings, but none confirmed.

The only way to really tell is to look at the hang tag on one of the diff cover bolts to see (anybody have a pix and a magic decoder ring for this). If that is gone, you can either find out by pulling the cover and counting teeth or by turning the wheel and counting the drive shaft revolutions method, anybody have a good writeup for this using both locked and unlocked difs?)

Some D35's came with a factory limited slip installed. Don't have any info if it was an option on the D44 or 8.25's.






Disclaimer: Chrysler/Jeep has a bad track record of mixing and matching axles depending on what they had on hand. This list is just a starting point. There is no substitute for crawling under the rig and checking to make sure.