Replacing Rear Pinion Seal= PITA!

[Ski Bum]

I've had an oil leak at the differential, where the drive shafts plugs in for a few months now. With the leak I have changed the diff fluid twice to make sure there was enough enough fluid to keep things lubed. I decided that it had gone on long enough and was time to attempt to fix it. I did some research and found that the rear pinion seal is usually the culprit. So I called the dealership and the next day they ahd the seal in for me.

Overall the install was fairly simple aside from trying to break loose the companion nut and prying out the old and desintegrated pinion seal. The service manual I have recomended holding the companion flange in plece with a screwdriver while trying to break loose the companion nut. That wasnt happening at all. I actually broke two screwdrivers and bent a few others in the process. Finally I broke out the impact gun and that took care of that, no problem. Once I had the old pinion seal exposed it took another hour or so to pry it out of there without causing "too" much damaged to the companion spline. After that everything else went smoohtly. I slowly taped the new pinion seal in place, greased everything up and bolted the driveshaft back in place.

I figured while I was under there I would also do the $5 carrier bearing fix and pumped 1 1/2 tubes of silicone into the carrier bearing brackets. Hopefully today after I refill the diff with oil and test her out I dont have any more leaks

BTW, I have an extra quart of Redline 75w90ns oil sitting around that was intended to replace the diff fluid in my old WRX. This is the oil with the "ns" designatation meaning it does not have the friction modifiers the others have. It is actually rated as a GL-5 oil. This is what the Redline site says about it:

75W90 NS

This GL-5-type gear oil doesn't contain the friction modifiers for limited-slip hypoid differentials. This makes the transmission synchronizers come to equal speeds more quickly, allowing faster shifting and much easier low-temperature shifting. Can also be used in racing limited-slip differentials where weak spring design causes too much wheel spin.

Will this be alright for my LSD 1G differential?

 

[mavisky]

Try doing an input shaft seal sometime. It's literally the last piece inside the transmission.

 

[prplhz96]

You do not need any friction modifiers in your rear diff. The viscous coupling is a sealed unit. So in other words, just plain old 80/90 will be perfect. You can shell out the extra couple of bucks, and buy better gear oil if you want(which is what you have now I think).

 

[Ski Bum]

You do not need any friction modifiers in your rear diff. The viscous coupling is a sealed unit. So in other words, just plain old 80/90 will be perfect. You can shell out the extra couple of bucks, and buy better gear oil if you want(which is what you have now I think).

Yeah the "ns" designation means that there are not any friction modifiers, which is probably why I got it for my old WRX. I guess I did alright then.

I drove the car for a bit today after filling the diff and so far no more leaky pinion seal!