Hi
What oil is recommended for an XJ40 3.54 standard diff?
Thanks
Pete

 

Your favorite brand of GL5 80-90 gear oil.
By the way, please tell us more about your car, maybe post a pic. Good luck!

 

The ratio is 3:58:1 and is identified by a red/yellow stripe on the rear cover area.
A red/yellow/black cross stripe denotes Powr-Loc.

This is for the 4.0 and 6,0 engine cars.
Powr-Loc needs the limited slip additive.