QuestionQUESTION: Howard,
How can I identify the type of diff I have ? I need to buy rear brake rotors but many sites refer to whether diff is Dana type or not when specifying rotors. I can't find anything in the manuals about which I have, they just refer to normal or Powerlock. I did find something on the web about the Dana not having a drain plug - mine has one and a filler plug. I also noticed the oil spec is different for each type.
Thanks,
Steve.
ANSWER: Hi Steve,
The only difference in the disks, between the "powerlock" (a limited slip)disks is that the "Powerlock" disks have holes in them to access the caliper mounting bolts as the standard differential had the mounting bolts heads on the other side of the caliper. Either disk will fit the standard differential.
BeckArnley quit stocking the disk without the holes because the one with the holes works for either differential.
The E-type Jag and the XJ-S had the limited slip and the sedans came without limited slip (Powerlock) but you could order it when it was new with the limited slip. Very few were ordered with the limited slip.
It is easy to tell if you have a limited slip differential. Just jack up the rear with both wheels off the ground and put the car in neutral (not Park) then hand rotate one back tire. If the other rear tire travels in the same direction you have a limited slip but if the other wheel rotates in the opposite direction, you have a non-limited slip differential.
The limited slip does use a different gear oil and must use a limited slip oil (some auto parts stores just sell standard EP-90 gear oil for both but sell an addative to put in the limited slip differentials. If you have a limited slip, and you can find the oil Jaguar recommends (BP Gear Oil 1453, BP Limslip Gear Oil 90/1 or Castrol G722, Castrol Hypoy LS.
Most likely you have a non-limited slip and just use EP-90 gear oil.
Howard
---------- FOLLOW-UP ----------
QUESTION: Howard,
I've got the rear suspension out of the car, I just tried rotating one hub, at one point the opposite did rotate in the reverse direction so I suspect I have the regular diff, not limited slip. I'm also going to replace the output shaft seals, there is lots of oil around them, wouldn't want to ruin my new pads. Do I also need to get new crush sleeves ? I've also got new pads for the hand brake, the Haynes manual says to replace the retraction plate, but I can't find anyone selling them - is that really necessary ?
Thanks,
Steve
Steve.
AnswerYes, You have to use new crush sleeves.
When replacing the hand brake pads I never had to replace any parts except I usually had to free up the adjusting screw and lube every moving part but I don't know why they would say that. I never had to replace either side plate.
Howard
