Pinion Seal Replacement

[WarrenD]

Great info, Gary and good timing. I was going to ask if 85-90 was ok. I know they say to use 80-90 but my local shop has 80-90 in a "new" formula for limited slip diffs (GL-5) and I think I'd rather stay with an older GL-4 rating as I'm not sure what the posi lubes do to old seals. I can get 80-90, but only in small bottles and the gallon is more economical as well as easier to use.
I have a puller for the flange if needed.
What did you torque the center bolt to when you put it back together?

[Cal_Gary]

I just cranked it tight (and aligned it to add the cotter pin). Sorry - i can't find my pix-must be on one of my CDs....
Gary

[WarrenD]

I tackled the pinion seal this afternoon, and 5 hours later, it's in. Worst part was getting the old seal out. Driveshaft nuts came off fine (in fact, a couple were not that tight....). The cotter pin was a pain, and the pinion nut was again, slightly less than tight. Companion flange came out with the help of a puller, but it was out in a few seconds. Now for the seal. I tried the drill holes, insert sheet metal screws and use puller, but I couldn't get a good bite on the screws, so I got out the Dremel with the cut off disks and started cutting and chiseling. Several hours, many disks and lots of cussing later, what was left of the old seal came out with the biggest pry bar I could find. Now it got easy. Install the new seal, block of wood and taps from a hammer and it was in. I used a speedi-sleeve on the pinion shaft as it had a slight wear groove and some signs of water damage. Measured twice, followed their directions and sleeve is attached. Flange went back in smoothly, tightened the nut and inserted cotter pin. How they got the cotter pin in is a mystery with the nut recessed into the companion flange. Noticed that when I took it out, had to cut and twist and then had a WTF moment when I went to put a cotter pin back in. Bolted up the driveshaft and test drove. I saw a slight weep but it seems to be neatsfoot oil, not gear lube. I had the seal soaking for several days so I think there was still some oil in it when I put it in.

Now, no job is ever finished and this one isn't either. When disconnecting the driveshaft, I checked the U-joints and the rear one is fine in one axis, but sticks badly in the other so it will have to be replaced. I'll do both on the rear axle at the same time. I will also have to take the driveshaft in as I felt a decent size dent in it when I was handling it. Not taking chances, I don't want to have to do another pinion seal any time soon.

[powerwagontim]

Hi Warren,
Congrats on getting it done!
Probably too late now, but did you think to put a dab of RTV around the back side of the pinion nut? Oil can seep out the splines and get out around the nut. Probably not much, and not worth losing sleep over if you didnt do it. Just something to be aware of, if you do see a bit of weeping, it may not actually be the seal.
Good job,
Tim

[vtdeucedriver]

Warren,
The trick to do that cotterpin is to get one that is "MUCH" longer than needed and put a slight bend in it then trim the ends once its in to bend it.

[WarrenD]

Hi Warren,
Congrats on getting it done!
Probably too late now, but did you think to put a dab of RTV around the back side of the pinion nut? Oil can seep out the splines and get out around the nut. Probably not much, and not worth losing sleep over if you didnt do it. Just something to be aware of, if you do see a bit of weeping, it may not actually be the seal.
Good job,
Tim

Yup, did that. I'll be dropping the driveshaft in the next week or two for repair, so any "adjustments" can be made then. I'm not driving it far until the u-joints are replaced, I don't want to damage the new seal, spent way too much time and effort replacing it. As of this morning, just a light film at the base of the seal, but it's neatsfoot oil, not gear lube.

[WarrenD]

Warren,
The trick to do that cotterpin is to get one that is "MUCH" longer than needed and put a slight bend in it then trim the ends once its in to bend it.

Would have thought just the opposite, but there is one in there!

[Cal_Gary]

Found the picture:

[WarrenD]

Thanks Gary. The flange isn't the problem, it comes off with a regular gear puller. It's the seal that's the pain to get out. So far so good on the pinion, but I have to re-do the T-case rear output seal, it started leaking again. Back to the leather seal and new flange, hoping the neoprene seal I just put in comes out easier than the leather ones.

[Cal_Gary]

Guess they aren't such a pain for me since I had to replace so many when I was on Active duty-lots of practice.... Next time I replace one I'll get those shots for you.
Gary

[pfrederi]

Now for the seal. I tried the drill holes, insert sheet metal screws and use puller, but I couldn't get a good bite on the screws, so I got out the Dremel with the cut off disks and started cutting and chiseling. Several hours, many disks and lots of cussing later, what was left of the old seal came out with the biggest pry bar I could find.

I actually had success with my front pinion seal 2 weeks ago using the sheet metal screw approach. Used # 10 screw. Drilled 8 holes around the seal then kept working my way around with the slide hammer. Had to use several screws as the threads got stripped fairly often. It took several trips around before it moved significantly and even then it took awhile to come out. When i did the back pinion a few years ago, like you, I wound up with a chisel, dremel and enough 4 letter words to turn the air blue.