Pinion seal leaking

[eREdge]

I have a 2WD 3.0 open diff and it's leaking from the rear

Question is, how hard is it to replace? I seen a video on a different vehicle and it looks as simple as marking the Nut, shaft and flange, counting or measuring threads and making sure everything aligns?
Someone said you can potentially ruin a rear differential if not done properly, so that's what scares me lol

Please list tools and parts that I'll be needing and advise is necessary, thanks.

 

[Curious Hound]

On the surface, it appears to be a simple " remove but, remove seal, install new seal, replace but" kind of job. But....

That but sets the bearing preload for the pinion bearings and there is a procedure for ensuring the nut is tightened to the proper torque to give that preload. Improper bearing load = possible bearing and gear damage.

The other thing to consider is, " why is the seal leaking?". It could be that your bearings are already beginning to fail, causing excessive play.

Or, it could just be an old failing seal.

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[Curious Hound]

Sorry. In that first sentence, that should read " nut" instead of " but" in a few places.

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[eREdge]

On the surface, it appears to be a simple " remove but, remove seal, install new seal, replace but" kind of job. But....

That but sets the bearing preload for the pinion bearings and there is a procedure for ensuring the nut is tightened to the proper torque to give that preload. Improper bearing load = possible bearing and gear damage.

The other thing to consider is, " why is the seal leaking?". It could be that your bearings are already beginning to fail, causing excessive play.

Or, it could just be an old failing seal.

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Yeah some say it's a PITA while others have said it's easy.
Do you think a shop is better off fixing this?

My vent valve was clogged and I think that's what caused the leak

 

[Curious Hound]

If you crawl under there and grab the pinion, can you move it side to side or up and down? That would be indication of bearing problems. Another thing to check would be the wear on the ring and pinion gears or look for metal particles in the gear oil.

Some might tell you to go ahead and replace the seal and just torque the nut to xxx ft-lbs. I'm not sure that is the best approach. Let's wait and see who else chimes in with advice. That torque value is around 250 ft-lbs if I recall. Takes a good bit of leverage to apply it.

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[Bird76Mojo]

I just did one on my 2004 8.8 axle in my V8 truck. Easy service.. Don't overthink it.

Just be sure to use the rod that comes out of the end of a caliper to measure from the end of the threaded section of the pinion, to the pinion nut face. Also mark them if you like. Remove everything to get at the seal and pry/chisel/hammer it out. I applied the thinnest layer (I MEAN THIN) of oil-proof gasket sealer to the outside sealing surface of the new oil seal before installation. I also had to make a seal driver to hammer it in place without bending it. Just a straight cut, 3" long or so, piece of large pipe that matched the seals diameter and a piece of 1/4" flat stock welded to one end to hammer on. Turning the seal driver assures it goes in straight. After re-installing everything in the correct order, use a VERY long breaker bar to tighten the pinion nut back to the original preload. You won't likely have enough strength to tighten it any more than it was originally. I'd even add the smallest amount more if I could, but with the 4ft breaker bar I used, we couldn't crush that preload collar any more than it was in the first place. Guys that service these axles use bars around 6ft long or more to crush the preload collar if that gives you any idea of what it takes to over-torque that nut.. Mine has been flawless and leak-free ever since and I beat the tar out of this truck every day.

Is this the "correct" way? Maybe not, but it's been done this way millions of times by shadetree mechanics everywhere, and if done correctly, it'll work fine for you. As long as there aren't any worn out bearings, etc.. As the previous posters have mentioned.



GB