Forum Discussion

oldmattb's avatar
oldmattb
Explorer
Mar 16, 2015

Leaking Rear Hub on DP



My hub started leaking recently. This will be my first experience with this.

First, I am assuming that this is likely just a leaking cover plate, and not a symptom of something serious. I see no cracks nor damage, and there appeared to be a piece of thin gasket material sticking out from between the plate and wheel. Second, I assume the lube is the same that is in the differential, since there are no caps or fittings to install lube at the wheel.

Third, I am thinking the repair would be to drain the diff, remove the plate, clean up the surfaces, install gasket and reinstall.

Am I on track? Is it necessary to drain the diff? Would blocks of a safe height under the wheels on one side keep the fluid at bay until I could to the repair? Should I use a factory gasket, or will RTV do the job?

Or am I way off?

Matt B
  • Oldmattb, ... both times my wheels were removed to avoid damage to the wheel openings when handling the axel. The outside hub and the axel are a single unit. Looking at your wheel you could probably pull the axel, clean it up and reinstall without jacks (no wheel removal). Cummins did mine both times and removed the tires/wheels to gain better access to the axle when removing it. Yes it's heavy.
  • I easily loosened one of the nuts with a socket and 8-inch handle. Maybe I should get a torque value and wrench the nuts down and see if that solves the problem?

    Matt B
  • Tires have not been off recently.

    No signs of oil on the backside, nor between the inner and outer wheels. It appears that the lube leaked from the outside axle plate and was driven by centrifugal force to the back side of the stainless trim cover.

    I looked for a diagram or photo of how the axle comes apart, but could find none. So the 12 nuts come off, the axle just slides out and the hub remains attached to the axle? Does the tire and wheel have to be removed, or can this be done as it sits?

    I am picturing removing the 12 nuts, pulling the axle out about 1/2 inch, letting some goo drain out, remove old gasket material and oil from mating surfaces, apply Permatex, tap axle back in, and install the nuts.

    I value your sage advice, but I don't see where the jacks and stands come in.

    Matt B
  • VintageRacer wrote:
    Most times when someone has a leaking rear hub it's the inner oil seal. If you have a leak at the axle gasket, then all you need to do is take off all those nuts. slide the axle out, clean off the goop and old gasket, and put it back together. A factory gasket would be best but I would probably use "the right stuff" from permatex/loctite. You don't have to drain anything, or take anything else off. That is not a cover plate, btw, that is the axle. It's about 3 feet long, has splines on the end that you have to stick back into the differential, and it probably weighs a hundred pounds or more. Easy job for a truck shop, btw, and if you ever get towed, the tow truck driver will pull out an axle and put on a cover plate so the transmission doesn't spin while you are getting towed.

    Edit: it actually looks pretty clean right around where the oil would be if it was the axle gasket. I might suggest getting a look at the back side of the wheels. If it is a hub, then it's a bigger job. It's not an super difficult job, it's just that everything is extremely heavy and the torque numbers are extremely high.

    brian
    Spot on ... ! I've had two axel hub seals fail ... the hub and everything around it is soaked before it makes it's way to the wheel where you can see it. I agree on the inner seal failure, not the axel hub.

    And the right tools, jack, and stands cost a lot more than the labor rate for a shop that does.
  • Most times when someone has a leaking rear hub it's the inner oil seal. If you have a leak at the axle gasket, then all you need to do is take off all those nuts. slide the axle out, clean off the goop and old gasket, and put it back together. A factory gasket would be best but I would probably use "the right stuff" from permatex/loctite. You don't have to drain anything, or take anything else off. That is not a cover plate, btw, that is the axle. It's about 3 feet long, has splines on the end that you have to stick back into the differential, and it probably weighs a hundred pounds or more. Easy job for a truck shop, btw, and if you ever get towed, the tow truck driver will pull out an axle and put on a cover plate so the transmission doesn't spin while you are getting towed.

    Edit: it actually looks pretty clean right around where the oil would be if it was the axle gasket. I might suggest getting a look at the back side of the wheels. If it is a hub, then it's a bigger job. It's not an super difficult job, it's just that everything is extremely heavy and the torque numbers are extremely high.

    brian
  • Have you had the tires off recently?
    If the tech wasn't careful when they pull the wheel off it can catch on the cover and damage it.

    Easy to fix.