Wheel Drive Oil Leak... Help!!!!!

[John L]

Hey guys:

So I was all fired up... I changed out all of the oils on the truck including transmission, wheel drives, front and rear diffs and reduction gear box. Took her for a spin and everything seemed much smoother than when I bought her a few years back. I finally got a chance to take her out in the woods yesterday. I didn't do anything crazy; but we went through some mud and water and I had a chance to engage the front and rear diff lockers and give them a bit of exercise that they don't seemed to get enough of. I hit a few bumps, but nothing out of the ordinary. The trip from the house to my lease is about an hour. Ride up and back was fine. When I stopped in the driveway to open the garage, I noted oil that seemed to be pouring out of the drivers side rear wheel. I got her in the garage and took some picks. The leak does not appear to be coming from either of the oil plugs. In the photos they may look a bit wet; but they are merely clean from my working around them last week. Note the oil that seems to be dripping from the housing. The entire inside of the wheel was full of oil. Another interesting note is that the boots seemed clean and dry. I did not open up either of the plugs to see if they are the one's that leaked; I just assumed it was a wheel drive leak given the location. What is wrong and what do I need to do to fix it? I looked at the drawings and I figured there was some gasket for the housing that must have leaked. But I don't see such an animal. Any thoughts on the cause of my trouble??? Thanks a ton for the help.

[John L]

The oil appeared to be coming from between the brake backing plate and the housing wheel drive. It wasn't just a drip; the oil seemed to be running out and you can see it was slung up on the inside of the wheel itself. I guess I am wrong and there isn't a gasket between the backing plate and the wheel housing. But, I'm confused as to what seals or rings could have gone out that resulted in the massive failure. Any thoughts would be greatly appreciated.

When I get time I'll jack it up and remove the wheel to see if I have the problem noted about the broken backing plate. But, with the wheel on there is no sign of oil dripping on the front of the wheel or the tire; just between the backing plate and the wheel drive housing.

Thanks

[pcolette]

I had something similar occur on the right rear wheel of my '72. Here's a diagram:

04-10.png (22.07 KiB) Viewed 8227 times

Item #11 (bolt retainer) failed and allowed item #10 (2 bolts) to propel themselves thru the brake backing plate. Gear oil flowed heavily thru the break and into the brake area before exiting similar to yours. Here's a photo of where the bolts were:

Pinz hub pc's.jpg (107.44 KiB) Viewed 8227 times

If you remove the brake drum you'll be able to see if this is what happened on yours. Hopefully you'll find it's just a blown seal. #04-10-17

[John L]

Thanks Paul. I had seen some posts about this type of thing; but I really thought there was a gasket failure between the two housing units. I had no idea that the gear oil was kept in place by the seals you are referring to. I looked into it last night and upon further inspection, the oil was coming from the weep hole at the bottom of the brake back plate just under the drain plug. So, I am assuming a failed seal and/or the sheared bolt issue you discussed. I'll search again along this topic and make sure I order the right parts. I'd rather have more than I need so I can finish it when I start it. Thanks again for the help.

John

[pcolette]

If the seal (#17) fails, the gear lube will flow out of that weep hole. In theory that is supposed to keep the gear oil from contaminating the brakes.

Paul U. "undysworld" did my repair for me because it was beyond my mechanical talents and required a gear puller I don't have. Hopefully you'll just need the seal and the o-ring (15).

Good luck!

[TechMOGogy]

Berger's thread may be of help to you (depending on what the problem ends up being): viewtopic.php?f=13&t=8356

[Jim LaGuardia]

The axle seals are offered in 2 sizes, 55mm or 60mm.
The 55mm spacers can be danged during removal(use a scraper and hammer at the base).
The 60mm spacers are easier to service but can be prone to pitting
So it is wiser to order 15,16, and 17 so the seal matches the spacer the first time

Use Permatex aviation sealant on the mating surfaces, do not use silicon sealer

[Andre]

And remember I'm close by in E Texas if you need help.

[John L]

Thanks so much for the input guys. I just ordered the parts (15, 16, and 17) and ordered them in both sizes hoping I can fix this in one shot. I guess if I pull the wheel I will know whether the backing plate got cracked as I'll see oil on the brakes. I'm hoping it is only a seal. If not I'll have to dig a bit deeper and get the other parts.

Assuming it is only a seal, Jimm mentioned using a sealer/adhesive on the mated parts... which ones will need the sealant on them?

I've looked in both manuals and the answer isn't clear. Thanks!

[undysworld]

I believe he's talking about between #1 & #4 as seen here: http://www.pinzgauer.com/parts.php?cat= ... view=04-05 where the machined surfaces mate.

[John L]

Paul you were unfortunately spot on with your diagnosis. After ordering the parts from Sarah just to replace the seal, spacer and O ring I decided to get a jump on the job and pulled the wheel and the brake drum. Oil inside the lower section of the drum and on the bottom of the shoes. Further inspection revealed some metal pieces and a crack in the brake backing plate up at the top. So, yesterday was a typical Monday!!!!

I read where someone had their backing plate welded/mended. Is this recommended or do I have to drop a couple of hundred bucks on a new backing plate???? I'll dig further into some old posts about this repair to see what else I will need. Paul thanks for the pics and the heads up. Jimm thanks for the input and Andre, I hope I don't have to call you but rest assured if I get in a jam you will be the man to get me out of it.

John L

[undysworld]

John,
I believe the backing plate can be welded, provided there is internal clearance where the repair will be. FWIW, I still have Paul C.'s old one, and I think it could likely be repaired. In case yours isn't (repairable), you're welcome to his old one if you want it.

[John L]

Thanks for the offer. I may take you up on it. Let me dig into it a bit more this weekend and see what I have. I haven't taken the brakes off yet to really see what kind of a mess I have. Once I do, I will let you know. Thanks again as I appreciate it.

John

[TechMOGogy]

Not to go off John's issue and I know this issue is a service bulletin
But is this something that 'should' be done regardless of condition or just done if your in there for other reasons?
Hope that even makes sense!
Thanks,
Dan

[pcolette]

Not to go off John's issue and I know this issue is a service bulletin
But is this something that 'should' be done regardless of condition or just done if your in there for other reasons?
Hope that even makes sense!
Thanks,
Dan

I suppose the answer depends on how much risk vs. effort that you are comfortable with. I've seen first hand what the retainer/bolt failure can do and what it can cost but since I don't feel I have the mechanical skills for this particular upgrade I've decided to take the risk and let it be. If you're already in there for something else I'd say go for it and replace the bolts and both spacers as a precaution. They're a lot less expensive than the backing plate.

One other consideration that I don't know the answer to is that the damage to the backing plate was bad enough, but when the bolt(s) break free can they also damage the gears?