Differential pinion seal replacement

[mjk164]

I have just replaced the pinion seal on the differential. The pinion seal is the oil seal around the pinion that connects the diff to the prop shaft. My car is 1993 960, 2.9 6 cylinder auto AW30/40, estate with solid axle, and about 360k miles. The seal started to drip oil and spray a nice anti-rust coating on everything to the rear of the seal. You need to buy a new seal and 2ltrs of oil ready for the job. Good advice on this forum (Driveshaft, Rear Axle Driveline, Rear Axle) is, don't buy a non Volvo seal; this is quite a complex seal and only OEM will do. I think the part number is 9143317. Run the car for a short while to warm up the diff oil ready for draining. Set the rear of the car up on a good pair of ramps and chock the front wheels; you are going to need one of the rear wheels jacked up to turn the shaft for access to the shaft bolts. I also make fast a line from the tow bar to something secure to the rear. When you think you are ready, release the handbrake and take the gearbox out of park. When you jack up a rear wheel, leave the ramp there. Drain the diff; on the 960 there is no drain plug as such, it is the center lowest bolt securing the diff end plate to the main body of the diff. Take this opportunity to release the filling and level plug, half way up the diff. Release the 4 nuts and bolts securing the prop shaft to the pinion. Before removing the shaft, mark with paint (or similar) the relevant position of the shaft on the pinion. If you don't do this, you may have to have the shaft re-balanced. To get to all 4 bolts you will need to turn the shaft...hence jacking up one wheel. You now need to remove the nut holding the pinion onto the splines and you will need to find some way of securing the pinion flange. There is a good description in the FAQ of this forum. This nut will be tight and you will need an extension bar to shift it. Once it is off, a simple puller on the pinion will release it and draw it off but note and mark which splines it comes off. Pulling out the old seal may be fun as its been there for a long time, and mine needed some heat around the metal part of the seal, to break the seal. A strong screwdriver will wrench it out. Be careful not to damage the splines. Once the seal is off its a matter of gentle cleaning up of the area, gently tapping in the new one....it will only go in one way and fairly obvious when you look at it. Tap gently until the seal is flush with the housing. Clean the pinion and a smear of oil on the splines and outside and out it on, followed by the nut. Harden the nut up and it need to be tight 148 to 184 Ft/lbs. Then reconnect the prop shaft back into the same position. Re-fill the diff with new oil. It makes it easier if you gently jack up the car body off the springs, about 3", will give you much better access to the filler plug to empty the oil from the filler bottle. Have a test drive and job done.