Rear differential service

[surferfletch]

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!

[amigo-2k]

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

[surferfletch]

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?

[wildlysmiley]

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

[Dober89]

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.

[surferfletch]

Do we have a limited slip differential?

Still no leaks, BTW!

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

[Dober89]

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.

[Gizmo42]

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.

[Gizmo42]

I would just like to thank everyone for jinxing me

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

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.

[Dober89]

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

[Gizmo42]

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