Rear diff started leaking. How stop it ?

Nothing wrong with ultra gray also a great product but a little to expensive for us to use in the shop for every day use because we use so much of it.

 

You probably already know..but did you just have rear replaced? Mayby even in last year or so? Some shops seem to not tighten up bolts like they should. Had mine leaking and the ones that were hard to get a air wrench on were not tight enough. Had to use 3/4 drive ratchet with cheater pipe. Took time to develop the leak. Otherwise, what they say.

 

We also use the 3M windshield adhesive in the shop to glue down gaskets.
It comes in a red and white tube and its yellow.
We affectionately call it yellow death because your not getting it off when it dries.
And don’t get on your hands because you will be wearing it a long time if you do.

 

I have 402’s and it leaks a few drops between the power divider and rear end(not the housing). My drivetrain man said to leave it till it’s time overhaul(bearing goes out or to much play). He said its not worth the work to take it apart and reseal it, it’s not just separate and reseal job. He’s the expert so I’m just taking he’s advice. Something about 402’s that has a narrow gasket on a certain section.

 

If its never been opened I would lean toward a plugged breather... Used to see this alot when I drove off road trucks.

 

I would check for the plugged breather first, but when it comes time for repair, get your mating surfaces clean and use this anaerobic sealer. There are other brands other than Permatex but it’s the same stuff, comes in a red tube, and is a purple gel, sometimes called Gasket Eliminator. They use this stuff to glue tractors together, especially when the housing is also the frame. Detroit uses it between the block and flywheel housing.

Anaerobic sealers don’t dry or harden until they are squeezed between to steel machined surfaces. After you torque it up it seals the bolts and everything, but the stuff that squeezes out does dry so the first power wash and it looks like there no sealant there, but it won’t leak, and it’s kind of like “breaking a taper” to get it loose.

When we reseal a diff in my shop, we remove the ultra gray the factory uses and this in its place. I do want to say, it DOES NOT work with a gasket.