Rear differential leaking

[AbramJ]

I know, I know, another thread from me.

Since I've been trying to work on my truck more recently I've been noticing more things.

My rear differential has always looked leaky, but I've been noticing recently that it's always wet, whereas before it didn't look always wet. I can see oil flung all around as well.

I've already bought a new cover gasket, a lube locker 12 bolt gasket. It looks like I need a new pinion seal too. I've watched a couple YouTube videos on changing that, but welcome more advice.

A few weeks ago I also noticed the breather tube wasn't plugged into the differential, so I put it back in and that seemed to be when the differential really started looking wet all over. Is the breather tube plugged up and causing some of my excessive leaking now?

 

[1300obo]

Looks like most of the leak is from the pinion seal, when I did mine I had the pinion and carrier out of the diff but I guess it would go like the videos. Pull yoke, pry out old, hammer in new, etc

 

[1300obo]

Have you taken out the fill plug? Looking at that vent makes me wonder if you got water in at some point

 

[HankScorpio]

A plugged vent will make a bad seal worse. When you change the pinion seal pull the breather off and clean or replace it.

 

[TJ1978]

Pull
Clean
Break clean 2 cans
Right stuff or the green gear oil permatex
Re fill

 

[AbramJ]

Thanks for the insights. Do you guys have a pinion seal you recommend, or will any of the various gm 12 bolt pinion seals work?

 

[Wes Harden]

Clean the breather, and the oil stain from the pinion. check the oil level. Drive it around for a bit and monitor the pinion seal, it may stop leaking after breather is clear.
When the diff get hot the air expands and needs an exit if the breather isn't doing it's job, a wheel seal or the pinion seal will do.