Leaky diffs

[DarkMan]

I've known for a while that my rear diff had a slow leak. Symptom of being the idiot stocker and rock crawling with no lift.

I'm wondering how big a job it is to change out the gasket. Could I do it in my apartment parking lot or am I better off paying a mechanic. What kind of diff lube is best for replacement (or topping off if nothing else).

Also, the front diff might be leaking. (I can't say for sure because my power steering leaks like mad. It had tranny fluid in it when I bought the truck.) I can't figure out how the front diff cover comes off. Do you have to take the whole Twin-I beam apart or what?

Any suggestions are welcome.

 

[Doug]

The rear diff is easy to seal. all you have to do is remove the cover, make sure the cover isnt damaged and then remove all the old gasketing material. Get some RTV sealant, put it on the cover and then put the cover back on. There is a fill plug on the front of the diff where you add oil. Actually before you remove the rear cover make sure you can get the fill plug out. it would suck to drain the diff and then find out you cant get the fill plug out. As for the front diff theyre a pain to get apart. the 3rd member in the ttb drops out i believe.

 

[RiverRat]

Are you sure the gasket/rtv is leaking and not the pinion seal?

 

[Brian1]

Trint, I recently changed my rear diff in my driveway. Pulling off the cover and draining the old stuff was easy. the harder part is filling it through the plug. You have more room if you jack up the rear of the vehicle so the rear axle droops down. It makes getting to the plug much easier.

For the front, I changed my oil and seals last year. You have to disassemble the whole driver side to get the diff out. You have to remove the rotors,spindles, axles on both sides and the radius arm on the driver side. If your seals are not leaking then you can buy a siphon pump from a store for about $5-$10 and suck out the old oil from the front fill plug.

 

[DarkMan]

Thanks Brian. that's really helpful. I don't really think that the front is leaking, since the cover isn't exposed like the rear is. It's just hard to tell because of all the pwr steering leakage.

River, I'm pretty sure it's the cover gasket. I don't see any fluid except for right along the bottom edge. I have hung up that diff a couple of times on rocks and I'm fairly certain that I've broken the seal. The edge of the cover is a little rumpled, not enough to worry about, but enough that it could have pulled the seal loose in the process.

Anyone have advice on what to use for replacment diff lube? I've never even shopped the stuff. I assume it comes in weights, like engine oil. Is that right?

 

[JamminG4Jim]

Originally posted by DarkMan
Thanks Brian. that's really helpful. I don't really think that the front is leaking, since the cover isn't exposed like the rear is. It's just hard to tell because of all the pwr steering leakage.

River, I'm pretty sure it's the cover gasket. I don't see any fluid except for right along the bottom edge. I have hung up that diff a couple of times on rocks and I'm fairly certain that I've broken the seal. The edge of the cover is a little rumpled, not enough to worry about, but enough that it could have pulled the seal loose in the process.

Anyone have advice on what to use for replacment diff lube? I've never even shopped the stuff. I assume it comes in weights, like engine oil. Is that right?

Yes, diff fluid comes in weights. I use Valvoline 80/90 up here in Minnesota. They've got some that goes up to 140 weight! Must be like syrup! :O)

When you pull the diff cover, just hammer the edge flat with a ball pein hammer and you should be ok.

Make sure you let the rtv gasket stuff set up for at least an hour before refilling the diff. There's a guy on this forum that had a REALLY good idea for filling diffs! Set the bottle up with a cap nozzle to accept a hose (they sell a fluid pump deal at Checker auto that screws right on the bottle). add a lenght of hose long enough to reach the diff fill hole. RAISE the bottle over the fender (like an IV bottle). Gravity does the rest! I use a hemostat (medical version of a hose clamp) to control the flow on and off. Works slick! I wonder who that was??? Can't remember right off hand.

Hope this helps!

Jim