Questions about differentials, gearing ect

[OverBoardProject]

I'm probably getting some used Cherokee differentials for a solid axle swap on my Chevy S10 Blazer, and I'm hoping that you guys can help me with a few questions.

1. Are there any years or models that are stronger?

2. Is there a quick or easy way to tell what gearing they have?

3. Do any have posi's or limited slips?

4. Are there any aftermarket manual locking hubs available for them?

Thanks in advance

[Ray H]

Originally Posted by OverBoardProject

I'm probably getting some used Cherokee differentials for a solid axle swap on my Chevy S10 Blazer, and I'm hoping that you guys can help me with a few questions.

1. Are there any years or models that are stronger?

2. Is there a quick or easy way to tell what gearing they have?

3. Do any have posi's or limited slips?

4. Are there any aftermarket manual locking hubs available for them?

Thanks in advance

1: A few 87-89 XJs have the Dana 44 rear axle option, usually with the tow package. The D44 is the strongest rear axle put in the XJ. The second strongest rear axle available was the Chrysler 8.25. The 8.25 was used from early 90s to 01. In late 96 they went from 27 spline axle shafts in the 8.25 to 29 spline which brought it up close to the D44 in strength. The Dana 35 was used throughout the XJ run when the other axles werent used. All later models with ABS used this axle. It is the weakest available.
As for front axles, the Dana 30 has always been the only front axle available on north american models. The earlier, 84-91 I think, used high pinion D30 with a vacuum disconnect that can be tempermental at times. In the early 90s the vacuum disconnect disappeared. In 00 they went to a low pinion D30. In late 95 the XJ went from 260 front u-joints to the bigger 297s in all XJs, before 95 only ones with ABS got 297 ujoints. In 00 they dropped the high pinion for a low pinion D30. So, the strongest front axle available is on the late 95-99 XJ.

2: Theres a metal tag on the diff covers that indicates the gear ratio. If the tag has been removed you can spin a tire and count revolutions of the driveshaft. Most XJs with auto tranny and 4.0 will have 3.55s, 4 cyl XJs with 5 spd will have 4.10s, 4.0s with 5 spd will generally have 3.07s, 4 cyl with autos will have 3.73s. Thats not etched in stone though.

3: Yes some do have rear limited slips. There should be another tag on the rear diff if they do.

4: Yes. Warn makes a manual kit for them.

On a side note, Im not a Chevy guy but If Im not mistaken, the Blazer has a 10 bolt rear. Unless you are going for a width change, its really not worth switching out the 10 bolt for any of the XJ rears except the D44 and they are few and far between. The 10 bolt has a better aftermarket than the 8.25 and a D35 is a step down.

[OverBoardProject]

Thanks for all the information Ray, that was more than I was expecting.

The reason why I'm switching the rear end as well is so that I have the same offset and bolt patern.
The S10 Blazer almost uses a front wheel drive offset to give the engineres some place to stick all the IFS stuff. As a result the quick way to tell a 2wd apart from their 4wd is by looking at the offset.

Plus the 4.10 gears just won't work with my engine swap. Unless I want to scream the motor going down the hwy. 3.55 is perfect.
I'm replacing the gas pig (15mpg) carburated 2.8L motor with a non turbo 6.2L Diesel
I just got tired of giving the gas companies my check when I realized it costs me around $300.00 more a month to run my Blazer than my car.
Plus I can't afford a new Liberty Diesel at the moment.

[Ray H]

Keep in mind that if you plan on installing a Warn manual hub kit that you can probably choose a front bolt pattern to match whatever rear pattern you have.

[OverBoardProject]

True, it's the offset that's the killer though. I've got a set of dual bolt parern wheels that I could us as well.

I'll probably leave the hubs until I work most of the bugs out. I've got a 4x4 posi lok that I can modify to make the hubs work for a while.

I'll be making a web page on the entire job, and post the link the moment that I have it started.

[Ray H]

You know that the D30 in Xjs, and YJ or TJs for that matter dont really have auto hubs that need to be locked? They have unit bearings that dont unlock, so the front driveline is always spinning, unless you put a manual hub kit on. The posi loc that is used with an XJ is only used for XJs with the vacuum disconnect in the front passenger axleshaft. This disconnects the pass shaft from the differential but the drivers shaft is still connected.