Working on a ‘91 XJ-S differential; don’t believe that it has ever been apart because the safety wire has been done well and only has 58000 miles, plus there is absolutely no sign of wrench marks anywhere. Even the brake pads (and definitely the rotors) are original.

Differential cover is sealed with form in place gasket (silicone). Appears factory applied. There is green and yellow aerosol paint marks (quality control) spanning the cover, the silicone, and the housing on the upper right. The parts manual does not list a gasket.

I know that the gasket from earlier models will work, as will most Dana 44 gaskets, but I am concerned about the speed sensor depth.

Does anyone know if the factory switched to form in place gaskets with the introduction of the cast aluminum cover and diff-mounted speed sensor?

 

I have the original differential from my 1989 in the garage with the finned cover. Never been apart and the cover is glued on. I put a 1996 differential in the car a couple decades ago and removed the cover for inspection before the install and it also was glued on with no gasket. Just make sure you put all the shims back on the sensor.

 

I think that is definitive, thanks!