rgr4475

Changing my differential fluid for the first time on my jeep and want to make sure I buy the right fluid.

Turbo X_J

Does it do a one wheel peel?

DFlintstone

This stiky from right up top ^ might help > https://www.cherokeeforum.com/f2/axle-info-148057/

Fred/N0AZZ

Or you could get a build sheet.

rgr4475

Honestly, I haven't noticed.

Looks like a Chrysler 8.25?

rgr4475

Ah, I didn't even think of that. I will get one, but was hoping to do this today in the meantime.

rgr4475

And is 75-90 differential fluid ok to use or do you recommend something else?

md21722

When you take the cover off you can look at the carrier and see if its LSD.

The owner's manual specifies synthetic 75w-140 for heavy duty use.

A lot of people ignore it and use plain jane 80w-90 especially if they're crossing a lot of water.

If you use synthetic you shouldn't need the LSD additive. You can also buy limited slip fluid and use it in an open differential.

Fred/N0AZZ

I change mine often off road a lot and creek crossings so I use 80-90w in mine. Do clean out the carrier and old gear lube with brake cleaner or the like then wipe everything out along with the inside of cover.


I bought aftermarket differential covers for mine and made sure that they had a drain plug also in them, because I change fluid so often. That way just drain inspect the old lube for any metal and to see if the cover need to be pulled or not. I still pull the covers at least 2 times a year to have a close look at everything. But the drains do make quick work of changing gear lube for sure went from 1 1/2 hrs. give or take to about 15 min. Here is a photo of my front D30 cover, rear is the same.

rgr4475

Thanks gents. So 75-90 is ok to use for normal street driving?

And could you guys take a look here. https://www.cherokeeforum.com/f2/let...e-game-210904/

I am thinking it may or not be related to why I am doing this in the first place other than it needs it.

87EagleWagon

If your Jeep has limited slip there will be a "caution limited slip" sticker in your glove box. In fact this is a AMC sticker that dates back to the mid 1960s.

Jeep Driver

There should be a tag on the diff cover.

If not-

Open on the left, LSD on the right.

md21722

^^ excellent picture.

8.25 axle are somewhat notorious for making noise. If you have the noise at any and all speeds over 25 MPH, carrier bearings are suspect. If acceleration or deceleration affects it, look to your pinion bearings. In some cases, it both. In any of the above are true, you're looking at an axle swap or a differential rebuild. This can NOT be done with simple hand tools. Axles need to be "set up" for proper pinion bearing preload and backlash even when using the same gear set. Minimum tools are dial indicator, beam type torque wrench or Snap On or equivalent Torqometer, and a tool to set the side adjusters - either make one or buy one from OTC or Miller (about $50). You'll also need pullers to remove the bearings and a way to install them.

In many parts of the country 8.25 axles for XJ's can be purchased for $100 so its almost always cheaper to do an axle swap unless you already have the tools.

75w-90 is fine, but if you have noise, I'd go with the 80w-90 until you figure out what the problem is. Using high dollar synthetic is a waste of money until you know what's going on.

I run Mobil synthetic 80w-140 in mine. Its as thick as molasses, and what is used in semi truck axles that call for synthetic, but it costs me $9 a quart compared to $20 a quart for 75w-140 a quart and I haven't had a problem in all the years I've been running it. I figure the extra thickness is good for any shock loading that might occur while off roading or winching out trees, etc.

Bluelight

One wheel peel is pretty definitive. Best bet really is to pop the cover. Build sheet or sticker is useful only if you are sure everything back there is original. If it happens to be your ride to the parts store, you can just pick up oil with friction modifier. It won't hurt to use it in an open diff and you'll be covered if you have an LSD.

rgr4475

Thanks gents, appreciate all the great info and pictures. If I can get everything figured out, I will update.