I use Valvoline Durablend 85W-90 which has the limited slip additive. It doesn't hurt anything to have it in there whether it has LSD or not, and the semi-syn oil is a good choice. I use a 1 qt hand pump with a 2 ft long clear poly hose that snuggly fits into the fil port to get the oil into the diff. Drain is the lowest case bolt.

I believe both differentials require the same oil, API-GL_5 (MIL-L-
2105 C or D) SAE 80W-90. It is a bear to get to on the independent rear suspensions. I decided not to try it without having a lift and had an independent garage do it. It makes it much easier to see what you are doing if you pull a wheel. I decided to use synthetic gear oil, partly because it is so hard to get to.

John

I don't know this for sure but I would guess that your diff may have what is called a "lock-up" rear -- my '92 940 Turbo had that type. In that case the oil to use would be normal diff lube--whatever the owners manual calls for.
If your car has a true "limited slip" you can determine that by lifting the entire rear off the ground and rotating one wheel by hand -- if the other rotates in the same direction you have a "limited slip" rear. The "lock-up" rear doesn't do that - it acts like a regular open diff with the other wheel rotating in the opposite direction of the one you spin by hand.
If you have a true "limited slip" you can use normal diff lube and add a specific amount of limited slip additive -- or buy premixed Redline brand limited slip lube. -- Dave

Dear hf63,

Hope you're well. There should be - on the differential case - a dataplate with the particulars of the unit. As I do not operate a 960, I cannot tell You the exact location. On 940s, the dataplate is on the axle tube, to the left of the differential housing, as one looks toward the front of the car.

Hope this helps.

Yours faithfully,

Spook