mountainmanjoe

I have a sweat where the drive shaft connects to my rear axle. That means I have a bad pinion seal right?
The replacement procedure looks really involved and requires special tools. It doesn't look bad enough to need fixing yet, but it may require attention down the road.

It seems odd to me that it's leaking already after only 60,000km (37,000 mi). Does that sound normal to you guys? What would cause it to fail so quickly?

toolhore

That doesn't look wet. I would give it a thorough cleaning, then watch it for about a week or so. Then make a decision on replacement or perhaps a sealer.

mountainmanjoe

It's obviously a slow leak. Not enough to drip, but enough to wick into the dirt on it. (wasn't there the last time I looked) Like I said, immediate attention is not necessary.

My main concern is why is this happening already with such low mileage.

tech2

just make sure there is fluid in it....they tend to stop leaking when the fluid get low lol.

why is it leaking...make sure the diff vent isn't plugged. If it can't vent, it will leak out the axle seals and pinion seal.

Its not that expensive to have repaired at a shop.

mountainmanjoe

Checked the axle today and the fluid level was fine, so I'm not losing much gear oil.

I also blew into the fill hole, and I could hear air coming out of the vent tube. So it's venting fine.

KChevy75

At around 45,000 miles the inner pinion race an and bearings went bad in mine. The little metal pieces then damaged the remaining bearings. I don't know why it happened at such low miles but it happened.

Yours could just have been a bad seal or some type of damage to the yoke that nicked the seal during installation.

It's relatively easily to replace but it's a process that must be followed exactly or you'll over crush the sleeve or under tighten the nut. When I rebuilt mine, I went with a solid sleeve with spacers which makes a rebuild much easier. Good thing because the new seal leaked and I had to remove and install a new one. No need to mark anything with the solid sleeve. Just torque to their specs.

mountainmanjoe

Hmm. That sounds bad. Maybe I should move it up the priority list.

Thanks, I appreciate the feedback. So much for GM quality control.

KChevy75

Oops! Somehow my response to what may have caused your seal leak got moved up with the issue I had. It kinda read that a leaking seal caused my bearing failure. That was not the case for me. It wasn't leaking.

I wouldn't be too concerned about your leak. I'd just keep an eye on it. Maybe check on it monthly or so.

tech2

I doing my front diff pinion seal tomorrow. I'm doing it the simple way. mark the nut and pinion with a center punch, remove it, flange and replace seal. Loctite and install the nut back a smidge past the original mark. I'll be done in 15minutes.
never had a problem doing this...no way am I going to remove the axles to measure tttr (total torque to rotate) or recrank a new crush sleeve. Some diffs allow a one time reuse of the crush sleeve if you add a small amount of original tttr measurement

mountainmanjoe

Thanks I'll keep it under observation.

Anybody know what the axle fluid change interval is supposed to be?

My owner's manual says: "Refer to the Maintenance Schedule to determine how often to check the lubricant and when to change it "

And then there is no mention of it in the maintenance schedule.