[abefromen]

'81 Formula with it's original 10 bolt 8.5
104K miles on it.

No gear noise but had some bearing noise and a real bad pinion seal leak when I got the car.
Took a close look at it. Noticed someone recently replaced the seal.

Definitely not leaking thru splines. It's past the seal. Flung on the tunnel and leaks when parked. Drips from behind flange on ground and runs to the cover and drips.

So, took it apart and changed the seal again using a NOS seal that even had a thin bead of sealer around the outside of the seal. Seal installed tight and thought all would be well.

Nope. Still leaked bad.

Just picked it up today from the drive line place because it needed new bearings anyway. Gave them another NOS seal and made them aware of the issue.

Brought it home and put it on jack stands at a slight angle and added about 4-6 ounces of gear lube. Leaks like a m-effer still.

When I tore the diff down before I dropped it off I inspected the seal area for any potential issues. Cracks, gouges, etc. Nothing.

Pinion flange is not grooved either. Look at the pic......it leaked THAT much at a slight angle in less than an hour.

WTF. Makes no sense.