Noticing some greenish oil around the rear of the car, and so guessing I have a differential leak. I have basically zero rear differential experience (the Caddy is FWD!), so I'm looking at the manual and trying to get my terminology straight.
Questions:
1) I think there are 4 possible leak points: the pinion seal (front of differential at the shaft from the transmission), an output shaft seal on each side, and a big cover gasket on the back. Do I have that right?
2) If yes to above, I'm guessing the pinion seal is a pain, but the other three are not too bad. Still correct? I'm guessing if I remove the plate at the bottom of the IRS I will be able to see more clearly...
3) To replace the seals, does the IRS need to be dropped for any of them? Any special tools needed? Is gasket maker used, or just dry seals?
4) This seems to be a nice video on how to change the oil, applicable to the Series III for the most part. Couple quarts of 75W140 oil?

Thank you!!

 

Four possible leak points: cover gasket, pinion seal, and the two stub axle seals.

The cover gasket is easy but the other seals are not. The pinion seal replacement can lead to bearing failure if not done exactly right. The stub axle seals are labor intensive.

Here's a write-up on changing the stub axle seals

https://www.jag-lovers.org/xjlovers/xjfaq/shaftseal.htm

Some outfits sell rebuilt stub axles (which includes new seals) that are easy to install.

Or.....just keep an eye on fluid level and clean excess leakage from time to time so it doesn't migrate onto the brakes

Cheers
DD

 

Thank you for all the info! I’d consider dropping the irs, but having to cut and replace the other exhaust pipe (I did one when I replaced the fuel tank) and the pinion seal sound like things I’d prefer not to mess with for now. Perhaps I’ll start with an oil change and assess from there.