Pinion seal replacement

[87geeinn]

Pinion seal is leaking like a sieve all of a sudden (hoping it's not the bearing). Shop manual says upon reassembly to tighten the nut 1/16th of a turn past where index marks are made. However, all of the reading I've done has people retightening the nut to the exact point where it was removed. Also, shop manual makes no reference to using silicone on the pinion splines...nor does it say to use RTV on the outside metal circumference of the seal which I've seen in several posts and how-to videos. Thoughts?

 

[mikestertwo]

First you should try to determine why the seal is leaking before you take it apart. Check to see if there is any side play in the pinion. If there is then either the bearings are bad or the nut has backed off for some reason. In both cases you will have to pull the pinion and inspect the bearings and races for excessive wear or pitting. If the bearings are bad then it's time for a rebuild. If the bearings are good then you could reassemble the pinion with a new crush sleeve and nut. Tighten the nut until there is 15-20 in/lbs. of preload torque on the bearings. Put sealer on the splines in the yoke. Put red Loctite on the treads of the pinion before installing the new nut. If there is no side play in the pinion upon inspection then do as the manual says as far as tightening the nut. Change the seal and tighten the nut about 1/16 of a turn past where it started to insure preload crush on the crush sleeve. Again use sealer on the splines and red Loctite on the threads. I have never put any sealer on the outside shell of the seal and never had a leak but I suppose it couldn't hurt.

 

[87geeinn]

Appreciate the response. I checked for play in the pinion by grabbing the driveshaft near the u-joint and yanking back and forth as hard as I could and there's absolutely no play. There's always been a slight leak at the seal but what concerned me is when I parked it last Friday and ended up with a nice puddle after it sat for three days. Prior to that, there were no indications of anything amiss and I flogged her pretty good. I'll be replacing the seal this weekend and take a closer look. I'm shipping the car overseas in about two weeks so I really don't have time for a rebuild....and the car has to be driveable with no leaks in order to be shipped.

When you say to use sealer on the splines, what type of sealer are we talking about?

 

[DarthBuick]

When you have it off check the pinion surface for a groove where the seal rides I think they make a redi-sleeve for it if has a bad groove.. Also make sure the vent is not clogged because if it is it can build up pressure when it gets hot and push out fluid. I always use permatex#2 on splines.