I've never done this before and would like to know if it's as simple as it seems, what gear lube you use, can I just clean my cover and paint it?
Just take the cover off, let it drain, spray it with some brake parts cleaner, seal it back up, and add fluid? Seems simple, which is why I know I'm wrong

 

Its that simple. Just make sure you don't over tighten the bolts, and make sure both the diff cover and mounting surface are uber clean before sealing with a paper gasket and thin film of red RTV on both sides.

As for reconditioning the cover itself, a wire wheel does WONDERS!! Then primer, paint, and clear if thats the route you want to go.

As for gear oil, 75-90 is good, but make sure you don't have a limited slip diff, otherwise you'll want something with the friction modifier.

 

So...how do you know if you have a limited-slip differential? I've got a 97 Country.

 

A few ways. What rear end do you have?

 

What do you recommend I clean the surface with before putting the diff back on? Roger on the wire wheel! RTV, is that just a sealant, just curious? I know I have a limited slip so what kind of friction modifier do you propose?

 

The bottle will say if its limited slip friendly, or that it has a friction modifier.

Wire wheel would work on the mating surfaces. Just make sure you clean up all the dust.

And RTV will help compensate for minor imperfections in the gasket or mating surface.

 

Okay thanks so much! Air spray and brake parts cleaner for the dust? Apply RTV generously or a continuous line?

Sorry for playing 20 questions, but would hate to get it wrong.

 

THIN film of RTV. Yes on the brake parts cleaner, yes on air.

No problem on the questions. Thats what we are here for.

 

Okay thanks so much! Glad to have my ducks in a row first!

 

i've never used a gasket. just sayin...

and i like ultra black rtv.

let the rtv sit on the cover for a bit, then install.
then let that sit for a bit before you fill it with gear oil.

 

What's the difference in RTV ultra black and red?

 

IIRC, black has a higher temperature rating, and possibly higher chemical resistance.

If you have a limited slip, Pennzoil Synchromesh is recommended for the LSD clutches.

 

Thanks for the input!!

 

Ok I must have missed something. How do you tell if you have the limited slip diff?

 

You can probably tell from the numbers on the diff, but the quick and dirty way is to lift both rear wheels off the ground, pop the trans into neutral and give one rear wheel a spin. If the other rear tire turns in the same direction- you have limited slip. If it turns in the opposite direction- you don't.