Hey guys,

Just wondered if this part is something that's a bolt off and swap. This rear differential is leaking where the finger is pointing. It looks as if the black casing comes right off to replace with a newer one, but just wanted to make sure and get some input on people who are more knowledgeable about the rear diffs on these cars.



Any input is appreciated, thank you!

 

There is a seal under the flange. It can be replaced but you should have someone do the work that knows what they are doing. There is a preload torque that is critical to proper operation, so you can't just swap the flange n

 

Awesome, now is that seal a metal seal that could be bent causing it to leak?

 

The outer edge of the seal is metal. The inter part is rubber and has a lip the contacts the lip in the flange and the pinion. .

 

Is this an AP1 car with an AP2 diff / transmission / prop shaft, or vise versa?
IOW: any indiaction this flange has been taken off before?

 

It's an ap1 diff. 4.77's installed, but leaks right at that spot in the photo where the finger is pointing to. Doesn't leak anywhere else, BUT there.

 

You can remove the companion flange and pry the oil seal out and reinstall a new seal and the flange. The Companion flange lock nut needs to be replaced too. You don't have to worry about spacers and all that mess, just torque the nut to spec.

 

What spec?
According to the service manual you find the spec by turning the pinion - in an empty diff!
(IOW: without the ring gear installed)
You can mark the position of the nut and re-tighten to that point after the seal swap but you'll be guesstimating the torque and pre-load on the pinion bearings.
It is not super-duper critical but if you overtighten you will damage your pinion bearings.
If you then back-off the pinion nut your crush sleeve will not uncrush and you end up with loose bearings.

That is the point Stratocaster was making: you need to know what you are doing

 

correct....there is NO spec. There is a wide range of possible ft-lbs to achieve the EXISTING turning torque, providing it has not moved...something tells me it has since its leaking. I've found that if that nut is not BRAND new AND loctited, it will move.

 

Sweet, so it looks like I'll just have someone else do it. Don't want to try this. I can rebuild a motor etc, but when it comes to clearances etc, I get a little iffy. Plus, I've never worked on an S2K before this. Thanks for the input guys, I'll look for the part numbers so I can get it rebuilt and have fun with those 4.77's.