G50 Differential Removal - Need the Basics

[Smoove1010]

I'm changing the input shaft seal on my '87 G50, and I'm concerned about pushing the new seal in too far, or losing a piece of the old seal (like the spring) inside the tranny. What do I need to know about removing the differential if I need to go in there to insure that nothing was left behind?

What torque value do I use for the 12 nuts that hold the cover on?

I assume both output flanges need to be removed - correct?

Can the o-ring that seals the diff cover be re-used, or is it a one-time use item?

Must the fluid be drained, or can I just tilt the beast on it's side?

It looks like the diff comes out and goes back in as a unit - are there any adjustments needed when doing a remove and re-install of the same diff?

Thanks to all in advance,
GK

[john walker's workshop]

you're over-thinking it. just swap out the seal.

[Smoove1010]

Maybe it was a self-fulfilling wish, but sure-nuf, after getting the seal out using the Sheetrock-screw method, I noticed the spring was not present on the back of the old, mangled seal.

Drained the fluid, popped off the flanges and cover, and there it was, dangling.

Now that I took care of that little set-back, anyone know the torque spec for the cover nuts and flange bolts? Bentley offers scant advice on G50 issues...

Thanks,
GK

[KTL]

When I had my trans drilled for the clutch shaft update, the tech said he sees old seals floating on the shaft all the time. Point being is that the wandering seal or spring does no harm.

The garter spring can come loose when tapping a seal in place. That's why you see in some service instructions to pack the seal with grease. The grease prevents the spring from popping off during install.

Torque value for diff housing cover is standard M8 spec 18 ft-lb (24Nm). Sorry, can't recall the axle flange center bolt torque off the top of my head for '87. 993 manual shows it being 32 ft-lb and they share the same basic differential and bolt size.

Yes you have to remove both axle flanges to get the diff out. And no there's no worry about the diff falling into the trans when you remove both flanges. The diff is supported by the side bearings, not the axle flanges.

You can re-use the existing o-ring seal if it comes out cleanly w/out tearing.

You can't just tilt the trans on the side because gear oil will come out the vent on top of the trans. Just drain it into a clean drain pan if its freshly installed oil.

No adjustments required to R&R the diff. Set it back in place and button it up.

[Smoove1010]

Thanks Kevin - yes it did look like the spring might even have hung on the shaft indefinitely, but with the engine and trans out, I figured I'd never again have this opportunity to pop the cover and take out the spring before it got loose, and probably mashed to bits by the beefy gears in that box.

New o-ring is already on the way - it's cheap insurance and re-assurance while it's easily accessible. Since I had to drain the oil, it's a good opportunity to swap out the Vavoline syn-power for something that doesn't have the LS additive - I'm looking for smoother 2-3 shifts, and non-LS oil purportedly gets the synchros in line quicker. We'll see about that.

Thanks for the torque specs and the primer.
GK