rear end is leaking out both ends!

[ehummelman]

I was out washing the car the other day and noticed that both rear wheels, rotors, pads, etc. are soaked in fluid. I checked the brake lines and MC and it's not brake fluid, so it has to be from the rear end. It's a Moser 12 bolt with Ford ends and Wilwood 4 piston calipers. I haven't pulled it apart to see what bearing/seal configuration is in there, but I understand that this is not uncommon and there's not clear agreement on what the problem is. Sealed ball bearings vs tapered bearings, different retainer plates, etc. have all come up in my quick research of the topic. I wonder why all of sudden this happened; I've driven the car for 10,000 miles with no issue and now it's leaking on both sides. I talked to Moser and they thought that it might not be a bearing/seal issue but that for some reason too much pressure built up and it spewed fluid. I haven't been driving it hard or on track so I'm not sure, again, why all of a sudden both sides leaked. Anyone care to lend some insight into what the issue might be? Maybe the vent got clogged or something? At any rate, I am guessing I'm in for at least new seals, maybe bearings depending on what type are in there, not to mention new pads since they're thoroughly soaked now. Any advice would be helpful, thanks.

[Rod]

after 10,000 miles I would say that its a cloged vent, if it happened right after install or service, then it was over filled

I have seen many use the fluild fill hole on the after market rearend covers as the fluild level hole and they always overfill

[Z06vet]

I have replaced 4 axles seals on my moser 12 w/ford ends. 2 on each side. I have around 7500 miles on it. I'm using C5 brakes, so all those adapter brackets sandwhiched together makes changing seals all that more fun... It seems to happen after long road trips. I had one crap out on the power tour, the other side after the powertour, and one after RTTH last sept. The other was just random i guess. One of several issues I've had with the moser. If you find any info on this please post it up. Scott

[T.K.]

Install a breather like the one in the art Morrison catalog. Then let us know if you still have problems

[Z06vet]

Not familiar with Morrison- have a link?
Thanks- Scott

[David Pozzi]

Some rear axles use a seal in the outboard end of the axle tube, just in from the bearing housing. If your axle doesn't have them, then it's using the bearing to do all the sealing. You might want to add them. This only applies to axles with sealed axle bearings.

[ehummelman]

Not familiar with Morrison- have a link?
Thanks- Scott

I believe this is what they're referring to.
http://www.artmorrison.com/2006cat/50.pdf

[Z06vet]

Thanks for the link.

[ehummelman]

Update - I pulled off the wheel, bearing retainer, and ebrake setup today. Turns out I have the sealed bearing with the o-ring and NO inner axle seal. Why the hell does Moser do that? Looks like I'm getting some seals and putting them in there. I think the bearings themselves are fine, so no need to mess with having them pressed off. Still, I am puzzled why they all of a sudden started leaking out both sides. Another stupid thing I'm embarrassed to admit, but I never realized that there is just the vent nipple screwed into the driver's tube - no hose or anything else. Just the nipple. It wasn't clogged though, so I would have thought that any pressure build up would have puked fluid from there, not past the bearings. I'm not feeling very confident that just new seals will fix the issue. I hate not knowing what caused the problem. Anyone have other ideas based on what I've described?

[gmc]

You definitely need the inner seals. The o-rings aren't really meant to hold the fluid in, more to keep dirt and debris out. Here are some part numbers for the inner seals incase you don't have them already. Install the seals and run a hose off the brass fitting and it should fix your problem.
Chicago Rawhide #15141
National seal #51098

[ehummelman]

Thanks for the part #s. Unfortunately, now I have to replace the pads and ebrake shoes, too. They're thoroughly soaked in gear oil and I don't think they'll work too well. Maybe I can wash them off and heat them up real good to burn off any residue?

[ehummelman]

Update- put seals in the axle tubes this weekend and got everhything all cleaned up. BTW, while #15141 seal will work, #15142 is actually a better option. Same exact ID, OD, and thickness, but the inner rubber seal is a double seal not a single. Hopefully this will take care of the leaks, now I just need to properly vent the diff and figure out how to make the Wilwood ebrakes actually hold the car.

[CarlC]

Sorry I did not see this sooner.

If the differential oil got past the bearing seals then the bearing grease has been contaminated. That will lead to much shorter bearing life.

[ehummelman]

Carl, I'm not sure I understand your comment. I've got the sealed bearings, not the tapered ones. Prior to me putting in the 15142 seals the only thing holding oil in the tubes were the little orings on the bearings themselves.