C8.25 Diff. Fluid Change

Hey just wanted to make sure on what type of fluid to add and if I need the friction modifier or not. I have a '97 XJ 4.0L AW4 with the C8.25 rear end. If I understand the Haynes right I use 5 oz of friction modifier with with the GL5(80W-90 or 80W-140) gear lube and RTV sealant for the diff. cover? Just wanted to make sure. Also I plan on changing my transfer case fluid. It's the NP231. Haynes says DexronII or III, or Mercon ATF fluid. Any recommendations(besides getting the rust off the axle:looney: )????

First clean everything up very good.
I like to use brake cleaner on the inside of the diff. But make sure to wipe out any residue or crud inside of it.
While you have it open inspect the ring and pinion for abnormal wear, and damage.
Do you have a limited slip rear end? If you don't friction modifier is unnecessary..

GL-5 in an 80w-90 weight for standard use or 80w-140 synthetic if you tow alot or use it in 'severe' service. (large tires and lockers are severe service).

Use RTV to seal the cover, and fill up to just below the edge of the plug. Its should take about 2 1/2 quarts to fill it.

For your transfer case Dex III is just fine. Just over a quart is needed here.

Um...yep, Bill pretty much covered it

My only suggestion is a Lube Locker gasket. Clean up the old RTV with a scotch-brite wheel

awsome i need to do this aswell mine looks worse then that uke:

97xjcrawler said:

Also I plan on changing my transfer case fluid.

Click to expand...

Take the fill plug out first before removing the drain plug. Everything else is just what w_howey said.

w_howey said:

Do you have a limited slip rear end?

Click to expand...

I'm really not sure if I do have the LSD or not. Is there a way to tell once I pull the diff. cover? I will probably just buy the friction mod. anyway

Drain plug on a stock 8.25 cover? I dont know if thats correct or not, i just did mine and had to pull all the bottom bolts out and loosen the top bolts to open it a little and then let the oil drain out the bottom.

carrlf said:

Drain plug on a stock 8.25 cover? I dont know if thats correct or not, i just did mine and had to pull all the bottom bolts out and loosen the top bolts to open it a little and then let the oil drain out the bottom.

Click to expand...

I believe what Maz is referring to is the fill plug and drain plug on the transfer case...not the differential.

97xjcrawler said:

I'm really not sure if I do have the LSD or not. Is there a way to tell once I pull the diff. cover? I will probably just buy the friction mod. anyway

Click to expand...

Yes... If you look down along the inside edge of the carrier where the side gear is at you can see the spring clips that are part of the retainers for the clutch pack.

Open diff on the left, Limited Slip diff on the right.



.