T-case fixed, now the pumkin's leaking.

[MustangAndy]

*sigh* I just can't win with the drivetrain lately.

Recently:
1) Had the T-case replaced (professionally) Wednesday last week.
2) Took it off-roading Saturday (also bashed up my exhaust, but that's minor)

So what am I looking at here? (besides the obvious like the leak, driveshaft and pumpkin)

Looks like it comes out of the input and runs down the pumpkin.

There's also moisture around the breather line.

Is there some kind of seal or did I really break something else? I had the truck in the driveway after I brought it home from the shop and there's nothing in the driveway from then, there's also nothing in my grandparents driveway either where I was staying. I think might have happened on the way home (100+ miles).

-Andy
D.J.O.R. Netzhauptmann

 

[manaen]

There's a seal where the pinion comes through the case, usually they only start to leak when the pinion bearing starts to wear out. Either way though to fix it you need to pull the gears out, I believe (not sure) that the seals insert from the inside.

I would check all the bearing in the rear to make sure there is no play. When you pull the gears they will have to be re-set with a dial caliper, and if your going to do all that you may want to (depending on the mileage) put new bearings all around.

This off roading stuff can get expensive....

 

[IZwack]

The seal goes from the outside so no need to pull the gears. However, some will argue that you should still pull the gears in order to replace the crush sleeve (which is a pain to set to proper spec). Most people dont worry about the crush sleeve and just pop the flange off, pry the old seal out, replace and reinstall the flange.

 

[manaen]

well that makes it a lot easier. However, just make sure your bearings are in good shape when replacing the seal.

 

[gijoecam]

You mentioned you had been off-roading... check that the vent line isn't caked with mud and plugged... It attaches to the top of the diff housing, and vents up near the rear wheel well IIRC. A plugged vent line causes pressure to build up inside the housing as it warms up, and that can cause the fluid to be forced out past the seal.

Worst case, a new seal is like $4. Make sure you set the torque properly.

-Joe

 

[MustangAndy]

Checked the breather last night and jammed 100PSI of air into it. All I got was a tiny drop of gear oil out of it. I also knocked and scrapped all of the caked on sand off of everything under there.

So how does one change said seal? Is there a write-up somewhere that I missed? Last thing, I f I have to take off the diffy cover I might as well install my new one from JTSmith. Which gasket making stuff should I get? Pepboys has like 12 different one from the same company. EDIT: This is what they have http://www.permatex.com/products/Automotive/automotive_gasketing/gasket_makers.htm

-Andy
D.J.O.R. Netzhauptmann

 

[corkey]

blowing air into that breather was not the greatest idea, , any kind of contaminants went right into the pumpkin, , whether it was water , or dust , neither is good for it, ,

 

[Turdle]

Get the ultra (mega) grey or black. It will look better.

 

[gijoecam]

blowing air into that breather was not the greatest idea, , any kind of contaminants went right into the pumpkin, , whether it was water , or dust , neither is good for it, ,

I'm hoping he meant that he pulled the hose off and shot air through it... How else would a drop of oil come out of it? But it merits asking: Please tell me you didn't just blow air into the open end??

As for the gasket material, pick up whatever type of RTV they have... gray, blue, and black will all work fine... gray and blue will remain more pliable than the black, so the next time you need to pop the cover, it'll require less scraping to seal it back up.

The keys with any of them I've found are as follows:
-CLEAN BOTH SURFACES!! A can of brake cleaner has always worked well for me. I squirt it on a rag to avoid spraying it directly into the diff housing. Make sure there is no residual oil on the surface. None of the RTVs will seal on an oily surface.
-Use a generous bead, going around all the bolt holes on both sides. Too much isn't going to hurt anything. No need to apply it to both surfaces... I usually apply it to the cover because it's easier to work with on the bench than laying under the truck, but to each his own.
-Torque the bolts gently and evenly. Work in a criss-cross pattern, not around the circle. Don't over-torque them. IIRC, the spec is surprisingly low... something like 24 ft*lbs, but don't quote me on that one. Just don't over-tighten them.
-LET IT DRY!!!! Give the RTV a good couple of hours to cure before refilling the diff. If you can let it cure overnight, that's even better.

Hope that helps!

As for the pinion seal, I don't trust myself... I found a local trans shop I trust to do my trans and diff work (except for the rear end lube). There are some things I'd rather pay someone to not screw up, although I know I'm fully capable. If I had a hoist, I might be more inclined to do those myself as well... Maybe in my next garage...

 

[MustangAndy]

blowing air into that breather was not the greatest idea, , any kind of contaminants went right into the pumpkin, , whether it was water , or dust , neither is good for it, ,

Took the hose off of the truck completely. Then wiped the axle area where the breather goes with degreaser. Then re-installed the hose.

-Andy
D.J.O.R. Netzhauptmann

 

[joshuaj0214]

The oil around the breather tube is normal. I've been under hundreds of vehicles and its wet around every one. That pinion seal isn't a bad job at all. The hardest part is retorquing the pinion nut when you reassemble it. Its hard to keep the pinion from spinning while trying to torque it to 135+ ft. lbs.