oil leak

Rolled Ranger · Feb 20, 2008

Ok, so i have a dana 30 out of an '01 tj in the front. This is my first 4x4 and dont have a whole lot of experience with this stuff. The spot where the little shaft comes out of the diff is leaking gear oil. I really have no idea but i think it is just some kind of a simple problem with an oil seal. Could this be something major that i need to just take the truck to the local 4x4 shop for or should i just tear into it and lean to try and replace these things myself?
I could take pics if that would help anybody who is willing to help me out.

Sasquatch_Ryda · Feb 20, 2008

Is it the pinion that comes out of the back of the axle that connect to the drive shaft or the drivers side short axle shaft that is leaking?

Rolled Ranger · Feb 20, 2008

You've got it! I am surprised that somebody was able to figure that out from my ramblings. I talked to someone today and he said it is the pinion seal. He said it would be $300-$350 to fix it because it will take about 4 hours in labor. Does that sound about right or is he trying to get one over on me?

Sasquatch_Ryda · Feb 20, 2008

It would take me about a half hour to replace a front or rear pinion seal, I would say 4 hours is a bit uncalled for.

AKBroncoII · Feb 21, 2008

4 hours may be about right. Doing it properly would require a new crush sleeve. With the crush sleeve, possible worn bearings from the seal leaking. It's possible to just pull the old one off and put the new one on. Honestly though, they always leak on the dana 30's, if it's not bad just leave it. Even with a new one it will start leaking within a few thousand miles.

Rolled Ranger · Feb 22, 2008

Thanks for the info guys. I guess it is not as bad as i thought. It's not a bad leak, just enough to leave a small spot in my driveway. I will just make sure I keep it full of oil.

gotmudd · Mar 15, 2008

Rolled Ranger said:
Ok, so i have a dana 30 out of an '01 tj in the front. This is my first 4x4 and dont have a whole lot of experience with this stuff. The spot where the little shaft comes out of the diff is leaking gear oil. I really have no idea but i think it is just some kind of a simple problem with an oil seal. Could this be something major that i need to just take the truck to the local 4x4 shop for or should i just tear into it and lean to try and replace these things myself?
I could take pics if that would help anybody who is willing to help me out.

if you check these out on a regular basis you can replace just the seal in about 30 min. w/out the crush ring AS LONG AS YOU DON'T USE A TORQUE WRENCH to put the nut back on. disconnect driveline at diff THEN jack up drivers side till tire clears ground take pinion nut off with half inch impact gun or half inch breakerbar and BIG pipe wrench by grabbing yoke with pipe wrench to hold pop out old seal with screw driver tap new seal in with small hammer instal nut tighten by hand with socket until end play same as before. [check end play BEFORE dissasembly] tighten so that you can still spin yoke freely, would advise removing some fluid before starting though less messy

Hahnsb2 · Mar 16, 2008

AKBroncoII said:
Honestly though, they always leak on the dana 30's

Yea, my buddies XJ has a pinion seal leak.

Tweeder · Mar 18, 2008

AKBroncoII said:
Honestly though, they always leak

bullshit. no axle just "always leaks". maintain that shit. if you can't keep seals in it, the housing is fawked, get a new one. there is no valid excuse for having a leaky rig. that's only fuel for the tree-hugging greenie wackos.

MAINTAIN YOUR FAWKING JUNK!!! :flipoff:

AKBroncoII · Mar 19, 2008

It's not the housing. The crush sleeve will allow movement and overtime the bearings will become loose. Causing the pinion to walk and the seal to leak. Almost every one I've seen leak, which is a LOT of them, has bad pinion bearings. It's not maintenance problems. It's just a turd. A lot more of the lower pinions leak. The high pinions didn't have a crush sleeve, they used shims.

4x4junkie · Mar 19, 2008

The crush sleeve itself cannot "allow" the bearings to become loose, the pinion nut is backing off.

While it's true a crush sleeve design does allow the nut to back off easier than on a shim setup, if you use a NEW pinion nut during FINAL assembly like you're supposed to (and use Loctite on it), that won't become a problem.

gotmudd · Mar 20, 2008

4x4junkie said:
The crush sleeve itself cannot "allow" the bearings to become loose, the pinion nut is backing off.

While it's true a crush sleeve design does allow the nut to back off easier than on a shim setup, if you use a NEW pinion nut during FINAL assembly like you're supposed to (and use Loctite on it), that won't become a problem.

pinion nut backing off :icon_confused:

that is a new one on me and i've run fullsize 4X4's all my life under some pretty harsh conditions and i have NEVER had one "back off" on me, of course i run D44'S & D60's. i'm not gonna stick my foot in mouth and say it can't happen on the 30's and the 35's, but it is a new one on me :c-n:

.and by harsh i mean to say that there ain't a hill i haven't been able to climb or a ditch i ain't been able to get out of [with enough room for momentum]

4x4junkie · Mar 20, 2008

D44 and D60s both use shims, not crush sleeves.

What I think happens, when real high torque is put to the pinion, the pinion shaft twists very slightly, which causes the crush sleeve to be crushed just a tiny bit more, leading to a reduction of the torque holding the pinion nut on. Then over time the nut begins to loosen.
Shims on the other hand cannot crush further, so you don't lose any of the pinion nut torque.

By far the worst axle for nuts backing off are Toyotas. Its extremely common to swap to a shim setup on these, although I would still say simply securing the pinion nut would keep it from backing off (something beyond the OEM method of "staking" the nut).

AKBroncoII · Mar 21, 2008

It is a very long sleeve as compared to the 9" sleeve. I've also never seen them come loose on the 30's. My guess is the pinion tries to walk and allows either the bearings to wear out or causes the crush sleeve to crush ever so slightly. This would cause the preload on the bearings to be less and pinion to walk even more. Over time it will all need replaced. Every one I've done required new crush sleeve, bearings, seal and nut. Not just the seal and nut. Nuts have never backed off.

oil leak

Rolled Ranger

15+ Year Member

Sasquatch_Ryda

TRS Staff - Retired

Rolled Ranger

15+ Year Member

Sasquatch_Ryda

TRS Staff - Retired

AKBroncoII

15+ Year Member

Rolled Ranger

15+ Year Member

gotmudd

15+ Year Member

Hahnsb2

15+ Year Member

Tweeder

15+ Year Member

AKBroncoII

15+ Year Member

4x4junkie

Forum Staff Member

gotmudd

15+ Year Member

4x4junkie

Forum Staff Member

AKBroncoII

15+ Year Member

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