Axle Leak?

**35th-ANV-SS** · 10-05-2009, 09:32 AM

A few months ago I had a Moser 9" TrueTrac rear end installed.

Over the weekend when I was washing my car I noticed quite a bit of grease on the inside of my right rear wheel.

Does the grease I am describing (dark in color, kinda thick and gritty) sound like axle grease?

If so, I assume this would be an axle seal gone bad on the Moser rear?

I am going to take the wheel off today when I get home to look at it closer and try to see exactly where it is leaking from.

**Wesman** · 10-05-2009, 03:36 PM

Well axles don't actually use grease, they use gear oil, which is a thick lubricating oil. Most axles require either 75W-90 or 75W-140 gear oil.

However, when the gear oil gets past the axle seal, it tends to gum up and form the dark, thick grease you are describing. Typically this is caused by either a bad wheel cylinder or an axle seal - and seeing as our cars use rear disc, that only leaves you with an axle seal as the source of the leak.

**Smittro** · 10-05-2009, 03:42 PM

Hey Jon that's your new rear leakin? I'd check to make sure you do'nt have a calipar hanging up causeing an over heated axle hub bro..

**thearborbarber** · 10-05-2009, 04:20 PM

or cut the seal with the axle splines sliding them in on install.

**35th-ANV-SS** · 10-05-2009, 04:46 PM

Thanks for the information guys. Yeah, that's the new rear end that I just had installed unfortunately. It seems to be a never ending battle with this vehicle. I am starting to wish I would have left the SOB stock.

I just noticed this over the weekend. I didn't notice it the last time I washed the car, which was probably two weeks ago or even the weekend before that.

If it is the seal, I am hoping it's under warranty from Moser and can have it fixed.

I will check the caliper. It seems weird that it would go bad all of a sudden (the seal that is), but I've seen strange things happen and well my luck isn't the best.

**35th-ANV-SS** · 10-07-2009, 04:36 PM

Update: I took the wheel off and the caliper is in perfect working condition. It is definitely gear oil that is leaking. I could see where it was leaking from behind the reluctor ring.

Ugh.

Any advice I can give the installer to keep this from leaking again?

The seal must have gotten scraped/torn while the axle was being installed I guess

Someone mentioned using a bead of RTV on the seal when reinstalling a new one. I assume this is the best solution?

**Hi-Po** · 10-07-2009, 05:13 PM

35th, I told you, you could call me

I also had this problem with 9". It just happens. Now, you paid for a professional install, and it just sucks they are so far away from you. The swap is really, really easy and shouldn't take you more then 1.5 hours. The seal is 7 bucks or so from NAPA. The only tooling needed is something to remove the old seal, and that same tooling will really help get the axle shaft out. Just needs a little tug. A slide hammer jimmy'd up works great. Let me know if you end up doing it yourself.

If your paying someone to do it, tell them to put a nice coat of oil on the ID of the seal, and then a light coat of common grease. It really needs something for lube as the axle shaft slides in. Then when you go to put it into the center section, care needs to be had not to use the seal as a prying point. Then, IMO... a bead of RTV around the OD of the seal before installation helps. I went as far to lay a small bead of RTV on the outside OD of the seal after installation. Its not going to hurt anything, and will be another layer of protection from coating your rim with smelly stuff.

**35th-ANV-SS** · 10-07-2009, 05:18 PM

Originally Posted by Hi-Po

35th, I told you, you could call me

I also had this problem with 9". It just happens. Now, you paid for a professional install, and it just sucks they are so far away from you. The swap is really, really easy and shouldn't take you more then 1.5 hours. The seal is 7 bucks or so from NAPA. The only tooling needed is something to remove the old seal, and that same tooling will really help get the axle shaft out. Just needs a little tug. A slide hammer jimmy'd up works great. Let me know if you end up doing it yourself.

If your paying someone to do it, tell them to put a nice coat of oil on the ID of the seal, and then a light coat of common grease. It really needs something for lube as the axle shaft slides in. Then when you go to put it into the center section, care needs to be had not to use the seal as a prying point. Then, IMO... a bead of RTV around the OD of the seal before installation helps. I went as far to lay a small bead of RTV on the outside OD of the seal after installation. Its not going to hurt anything, and will be another layer of protection from coating your rim with smelly stuff.

You are the man Ron. BTW - After talking to GTP, the thought of the 4 bolts on the backing plate coming loose came up. That would be a really easy fix. I'll check that tomorrow night. If they are loose, I will pull them and use some lock-tite on them to prevent it from coming loose again.

Thanks for your input!

**Hi-Po** · 10-07-2009, 05:23 PM

Originally Posted by 35th-ANV-SS

You are the man Ron. BTW - After talking to GTP, the thought of the 4 bolts on the backing plate coming loose came up. That would be a really easy fix. I'll check that tomorrow night. If they are loose, I will pull them and use some lock-tite on them to prevent it from coming loose again.

Thanks for your input!

I would be shocked if they didnt use loctite AND lock washers.

**35th-ANV-SS** · 10-07-2009, 05:28 PM

Originally Posted by Hi-Po

I would be shocked if they didnt use loctite AND lock washers.

I would be too considering they install these all day, every day. But, you never know I guess. Easy enough to check.

**bills98ta** · 10-08-2009, 04:15 AM

If it is the seal, pull the 4 bolts, and the axle slides right out. Get a new seal & put ultra black on the outside of it & tap it in.

**bills98ta** · 10-08-2009, 04:16 AM

Oh ya, make sure the car is tilted so the gear oil runs to the other side !!

**Hi-Po** · 10-08-2009, 03:30 PM

Originally Posted by bills98ta

Oh ya, make sure the car is tilted so the gear oil runs to the other side !!

That, is a damn good idea! I thought of that AFTER I yanked the axle out

**35th-ANV-SS** · 11-01-2009, 06:17 PM

Took the car to Bob at EPP last Friday. Got the seal replaced. This weekend went to clean the car and the seal is leaking again.

FUUUUUUUUUUUUUUUUUUUUCCCCCCCCCCCCCCCCKKKKKKKKKKKKK KKKKK

Looks like I will be replacing it myself because I can't afford to keep driving it out there.

**bills98ta** · 11-02-2009, 12:18 AM

Originally Posted by 35th-ANV-SS

Took the car to Bob at EPP last Friday. Got the seal replaced. This weekend went to clean the car and the seal is leaking again.

FUUUUUUUUUUUUUUUUUUUUCCCCCCCCCCCCCCCCKKKKKKKKKKKKK KKKKK

Looks like I will be replacing it myself because I can't afford to keep driving it out there.

Think he used some ultra black sealant on the outside of the seal ?
This time, check to see if you might have a defect of some sort causing the leak... That's a bummer...

**35th-ANV-SS** · 11-02-2009, 03:00 AM

I mentioned the RTV or silicon and they said they NEVER have an issue with them leaking. The seal was installed wrong from Moser they claimed and that is why it was leaking.

Now I am wondering exactly what you said; something wrong that is causing it to continue to leak...

Seems like using RTV is putting a band-aid on the situation IMO. A rear-end of this caliper should not have any issues.

**bills98ta** · 11-02-2009, 03:17 AM

If there is a small scratch or dent, the silicone would take care of it. I always use ultra black on seals. Even the front & rear mains on my motor.

**AFASTYZFR1** · 11-02-2009, 03:26 AM

Originally Posted by Hi-Po

The seal is 7 bucks or so from NAPA.

have the part #?

**35th-ANV-SS** · 11-06-2009, 04:50 AM

Originally Posted by AFASTYZFR1

have the part #?

I called Moser and they told me for the 3.150" size, the axle seal # is CR15142. I don't know what the cross-reference is through NAPA or O-reily's yet though.

**35th-ANV-SS** · 11-06-2009, 06:48 PM

Originally Posted by bills98ta

If there is a small scratch or dent, the silicone would take care of it. I always use ultra black on seals. Even the front & rear mains on my motor.

Update. I bought the seal, seal removal tool, and some high-temp RTV. I rented an axle puller. I pull the axle out and the first thing I notice is that the seal looks a little caved in. Also, I am almost 99% positive the seal was installed backwards.

The spring on the rubber seal portion faces the differential correct?

Anyway, upon getting the damaged seal out I notice all kinds of scare marks where the seal surface would sit. So I make it as smooth as possible and clean everything with brake cleaner.

I put RTV on the lip seating surface inside the axle tube then pressed the seal in. Then I put RTV around the outer edge where the OD meets against the ID of the axle housing.

I left the car jacked up to the one side. Not going to mess with it until tomorrow late afternoon. RTV should be fully cured by then. Everything went back together relatively easy.

Keeping my fingers crossed it won't leak this time.