How hard are Diff seals to do yourself?

I was just adding Permatex the crud out of those out differential gaskets while you have it apart.

I love that permatex aviation gasket sealer.

 

Make sure the rear end vent isn't plugged up or you will be doing it a 3rd time.

 

that and make sure the driveline is running in balance. If it was just done a year ago and leaking again, something is likely up that’s causing the seal to leak, because those usually last a hell of a lot longer than that if everything is running right.

 

Drivelines slightly out of balance can also cause headaches like this. It will tell on it somewhere.

 

Ford makes some bad ### stuff too. The grey stuff they use to seal the pan on a 7.3 engine.

 

Replace the yoke. There not that expensive. And install with new seal. I kept replacing seal. Finally replaced the yoke and never leak again. The speedy seal kit didn’t last either. And never used the same locking nut. Buy new.

 

Pull the driveshafts and send 'em to a balance shop.

I guess you could jack up the whole rear end and spin it to about 25MPH on jacks and rig a runout gauge on the driveline, just make sure insurance is up to date, including life...