Is this a pinion seal leak or something else?

[Keseleth]

Hey all,
I haven't done much to the undercarriage of any vehicles before, so I hope you'll forgive my inexperience.
Two weeks ago I purchased my first Jeep from a private seller, and in the process of cleaning it top-to-bottom noticed the rear axle was covered in moist muck. I scraped a bunch off to see if I could see what was going on, and also found some strange silvery sealant I'd never seen before. The silvery stuff (I want to call it caulk, because its rubbery) was only on the part of the axle covered in goop, so I'm wondering if it was some kind of half-@ssed repair attempt.
Any opinions on whether or not this is/was a pinion seal leak or something else, and any guesses on the silvery caulking would be greatly appreciated!

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More views of it here: Jeep Liberty Renegade Rear Axle | Photobucket

Thanks in advance!

 

[tjkj2002]

The pinion seal is up towards the front where the driveshaft/u-joint meets the rear diff and that looks all dry in those pics.

It looks like a axle tube is leaking where it is pressed into the pumpkin.It has been known to happen and not cheap to fix.Can be caused by the axle tube turning(breaking the plug weld),or accident damage(a alignment can show that info).best way is to 100% clean the diff,make sure it's full of gear oil,and drive for 25-50 miles at highway speeds.Stop and take a look,if nothing is showing just keep a eye on it everyday till you spot the exact spot, hot gear oil will leak better then cold gear oil.


If it is indeed the tube leaking where it's pressed into the pumpkin a specialized diff shop can fix it and if the tube and/or pumpkin is damaged some places can re-tube but nothing can be done to fix a pumpkin so a replacement diff will be needed.

 

[u2slow]

^ What the other guy said.

If that were me, I'd be looking at a TJ Dana 44 to put in. Or at least an excuse to get another axle in whatever ratio I wanted. :cheers:

 

[Keseleth]

Thanks guys!

You've definitely given me a good place to start. I just picked up some foaming degreaser last night so I can finish cleaning the diff (and probably everything else while I'm at it...urgh).

tjkj2002 -- You mentioned a tube leak could be caused by the axle tube turning; can you tell me what causes this to happen in the first place? A loose or defective part? Poor construction? If the tube does turn out to be the issue I don't want to fix it only for it to happen again, if you know what I mean. I'm pretty sure it hasn't been in an accident (at least not bad enough to need reporting). Thanks again for the info, btw!

u2slow -- I'd love to get a new one, but $$$ is a major issue at the moment. I've seen the TJ Dana mentioned alot on the boards here, but I'm admittedly clueless on diffs and ratios. Most of my experience lies with bodywork and fabrication. Do you know any good resources for reading up on them? Thanks again for the suggestions!

Wish me luck! It's about 95F outside and I'm stubborn enough to brave it for the Jeep... :sparta:
Thanks all!

 

[tjkj2002]

tjkj2002 -- You mentioned a tube leak could be caused by the axle tube turning; can you tell me what causes this to happen in the first place? A loose or defective part? Poor construction? If the tube does turn out to be the issue I don't want to fix it only for it to happen again, if you know what I mean. I'm pretty sure it hasn't been in an accident (at least not bad enough to need reporting). Thanks again for the info, btw!

Can be caused by many things.If the KJ was hit on that side,or a curb hit,and hit that axle hard enough it could have broken that plug weld which would allow the tube to spin in the pumpkin.Alot of heavy towing will do the same thing as will doing alot of "N" drops.

 

[JeepCoMJ]

I'd tend to lean TJKJ's way on this, except that every old xj/mj/tj/yj/fsj axle i've ever seen has the same issue after it's been well used...and usually i find that the diff cover seal is leaking out just a bit.

a leaking axle tube wouldn't explain why the grunge is higher than the tube, as well.

axle breather is on the opposite side, but if it's venting up it could be running across the floorboard and dropping back down.

Either way, when it gets gummed up like that, it's not even close to a fresh leak. that's been a slow weep the entire life of the KJ and I would not worry about it.

 

[Keseleth]

I've done some more cleaning (pardon...excavating), and it's looking like it might be a combination of a plugged vent and leaking axle tube. I won't know for sure on the vent until I can get a mirror and a light up in there to see it. (I don't have a jack or ramps, so it's Twister time. :icon_sad
Either way, I picked up some RTV to re-seal the tube. Any suggestions on whether I should scrape the old sealant off first? Or would it be okay to just clean it and put the new RTV over the top?

JeepCoMJ -- Thanks! I'm glad to know I don't need to worry about it too much. A slow leak I can deal with, anything more and I'd be needing to sell off body parts!

Thanks again for the replies!

 

[Porkchop]

Dang I was hopping you would have to sell off body parts, I can always use an extra hand. LOL

 

[dude1116]

...as will doing alot of "N" drops.

Oops. That's what I get for having this Jeep since 17.

PS - She's a good looking Jeep! I hope everything works out!!!

 

[Keseleth]

Hey all,

I got it all cleaned up, and the vent/breather looks clear from what I can tell. (When I took the Jeep in to a shop to get a tire repaired, I asked the guys to check on the vent. THREE guys checked and couldn't find it!) Researched it at home and finally discovered it was a tube on the axle...:shakehead:

The fill cap seems to be leaking, in addition to the 'hole' next to the pumpkin. However, I still can't figure out where all the crap collected on top of the axle/pumpkin came from. Grrr.

Should I put RTV around the fill-cap? Any suggestions?

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-(pic)Top of the axle

-(pic)breather tube

Porkchop -- I'll let you know if I have to start listing them on Craigslist!

dude1116 -- Thanks! I've got a list a mile long of things I need to fix on it.

Thanks again!

 

[tjkj2002]

A little weepage from the fill cap is no issue.The far right circle in your pic is the factory plug weld that holds the axle tube in the pumpkin.

 

[Keseleth]

A little weepage from the fill cap is no issue.The far right circle in your pic is the factory plug weld that holds the axle tube in the pumpkin.

Thanks, tjkj2002. I didn't know what those 'holes' were called. Judging from the fact that someone tried to seal it before, I'm guessing the plug weld must've been damaged, thus the leakage.

I'm debating just pulling the whole sucker apart and replacing the fluid...but we'll see.