I've got a small gear oil leak on the back left. (I topped it up and added a dab of engine leak stop fluid.) I read that slightly bent axle shafts wear the seals faster and cause these leaks. I've got spare shafts in the spare axle, but Pablo is an 8" diff, where the parts truck is a 7.5".

Any chance they used the same axle shaft? Or do I need to go look for a shaft from a truck with a G-code axle?

How hard is it to swap out that axle shaft and seal?

 

I can't Rember for sure ... But I believe 7.5 diff is 28 spline and 8's are 30 spline axles
But there are do it yourself fixs remedies for bent axle tubes . And rear bearings aren't to hard but can be stubborn sometimes a good claw puller helps if the outer race is stuck

 

Not a bent tube. Potentially a bent shaft.

 

O okay they can straighten those to proably easier to pull a set from another truck or just find a whole g code rear end for parts and such

 

Yeah, that's my dream. I went and looked at an axle yesterday. Unfortunately the seller knew what it was worth. And it was a 6-lug. And it was a 3.90, which isn't the 3.72 I'm dreaming of. If only someone was giving away a G302 axle within a few miles of me, that'd be cool.

 

Okay, here's a bit of good news I ran across: One of the most common causes of axle seal failure is a plugged breather, which is easy to replace. This lowers the chances that my problem is a bent shaft, and makes it more likely I can just replace the seals and bearings and be good to go. Of course I'd still like a faster 3rd, but all in good time.

 

99.99% chance your shaft isn't bent. If the gear oil is only on the backing plate and housing you need an inner shaft seal. If it is inside the drum its an outer seal along with the inner and likely the bearing is going bad as well.