Rear differential service

I can't remember the last time I swapped the fluid. The recent thread by amigo-2K had me thinking about it, so I pulled the Rodeo into the garage when the afternoon rains started coming down. I pulled the drain plug and found some metal paste on the magnet. I thought I'd better drop the cover since I think it's been about 3 years.

The bolts all broke away easily. I wonder if I undertorqued them last time. I used the paper type gasket painted with Indian Head gasket shellac, and I never had a leak. It was a little tough to pop the cover off, and half of the gasket remained on the cover, half on the housing. It took a good 30 minutes to scrape the old gasket off the cover. Indian Head is pretty good stuff! I dreaded having to get it off the housing with the brake line and other stuff in the way. I jacked the rear a little higher and got under it. It came off the housing much easier. Maybe 10 minutes. I sprayed everything down with intake cleaner and dried it out. I wire brushed the bolts clean. They were in good shape on my FL truck - very little rust. I put a bead of Permatex Ultra Black aroung the cover and it's setting as I type.

I'll fill it with some 80-90W and call it a night a little later. Hopefully it won't leak!

Cool. I just got back from taking my Amigo for a ride and a fresh peice of cardboard is under the diffy now .....

Hope it stays dry!

Mine has taken its maiden voyage and it's still dry.

I was glad I had no bolt trouble. Being a FL truck makes a difference. The Jeep, a '97, spent one winter in NC before I bought it, and I was worried about snapping one as you did.

I had a little pressure release when I took the plug out. The vent is clear. It must vent to a closed system which can build a little pressure, no?

I have been told it is time to sevice mine, is there anything I should know?
Jan.

I would just make sure you get the right limited slip additive added to the gear oil. Unless you get something like redline that already has friction modifiers in it.

Do we have a limited slip differential?

Still no leaks, BTW!

After researching, my '97 LS 4x2 doesn't have a LSD....

Pretty sure the 4wd systems have LSD. I know when I got all my drivetrain fluids done at 100k they was some additive they put in the transmission or the transfer case, I cant remember which one.

All '98+ 4wd rodeos should have LSD. I say should because I know of one that doesnt but think the rear end was changed in it. I dont know about the pre 98 ones.

I used Valvoline SynPower 75w90 synthetic in mine. It doesnt need any extra addatives.

I would just like to thank everyone for jinxing me :disappoin

While checking the under carriage y'day for any damage from offroading I noticed gear oil on my spare dripping. And dripping from the diff cover. When I left work today there was a decent sized puddle under the diff. So guess what I got to do today when I got home :banghead:

No signs of anything hitting it, think it just picked this time to go from a slight weep to an all out drip.

I now have a paper gasket with a light coat of red rtv on each side. And bolts torqued to 25 ft lbs (decided to split the difference). I noticed the face of the diff isnt machined all that smooth so thats probably why the paper gasket alone doesnt seal all that well. Next time I might just rtv the diff side of the gasket then coat the cover side with anti seize. Then the gasket can stay in place and I shouldnt have to scrape it off. Not sure about that method yet.

Did you make sure the breather isnt clogged? When I got my truck the diff was leaking but the breather was all plugged up.

Yep its clear. Just wasnt sealing right and synthetic will sneak out any little place it can find. Its almost as bad a bunker fuel oil. It better not leak again now, made my pretty chrome all oily :rofl: