Annoying D30 pinion leak

WB9YZU · Nov 30, 2013

The reason I put this in Modified is because of the parts used.

I have a SOLID cover and Motive Gears.
So I replaced the gears due to a failure. I replaced all the bearings.
The 1st pinion seal leaked, so I replaced it again, it's still seeping from the seal.

The SOLID cover has the fill hole above the axle as opposed to the stock cover which has it slightly below the axle. The axle is filled to the fill hole.

Is it overfilled?

-Ron

GrimmJeeper · Nov 30, 2013

most aftermarket covers have the fill hole higher than the original position, AND stick out farther than stock. both would allow more oil volume. that could be your problem but i'd guess that the axle seals would leak before the pinion would start seeping.

Tim_MN · Nov 30, 2013

Crappy seals ? Lube them upon install ? Is the pinion rusty or rough where the seal sits ? Any excessive gear oil will barf out the from vent tube.

01upcountry · Dec 1, 2013

Mine has a sheen to it also .....Its not leaking bad enough for me to tear into it and I have a gear install coming up real soon so its just going to be a pissy bitch till I do gears.
I too noticed the fill location difference between D30s I bought a cover to build a front diff. guard .

WB9YZU · Dec 1, 2013

Grimm, that's what I figured also. However, I don't see wet axle tubes.
Forgot to mention that it is a LP D30, so at the SOLID's fill level, the pinion is completely submerged.

Tim_MN said:
Crappy seals ? Lube them upon install ? Is the pinion rusty or rough where the seal sits ? Any excessive gear oil will barf out the from vent tube.

Good suggestions, but I thought of those.

The 1st seal came with the install kit (unknown brand).
2nd seal is a Timken.

Both were prelubed.

The yoke did have some pitting at one spot, and I cleaned it up with some 600 grit.

I'm thinking that it would take some serious effort to 'barf' 90w gear oil 3' up a 3/8" vent hose. However, I don't see any evidence of that, just gear oil dripping off the diff after I've stopped. Since the seal is wet and the bottom of the pinion area is wet all the way to the bottom of the housing where it drips off, I figure it's coming from there.

markw · Dec 1, 2013

Is there a groove in the yoke where it rides on the seal?

GrimmJeeper · Dec 1, 2013

unless he put used gears in there I doubt it, he mentioned in the first post he replaced the gears due to failure guys.

markw · Dec 1, 2013

The seal rides on the yoke, he put in new gears. He didn't say he replaced the yoke. I don't know how many times I've told guys. If you don't replace this yoke, it's going to leak and the didn't want to spend the money only to have it leak, and replace it later. Nice thing about a D30 is you can just pull the yoke and swap it as there's no crush sleeve.

rockclimber · Dec 1, 2013

WB9YZU said:
The yoke did have some pitting at one spot, and I cleaned it up with some 600 grit.

replace the yoke.

I'm thinking that it would take some serious effort to 'barf' 90w gear oil 3' up a 3/8" vent hose. However, I don't see any evidence of that, just gear oil dripping off the diff after I've stopped. Since the seal is wet and the bottom of the pinion area is wet all the way to the bottom of the housing where it drips off, I figure it's coming from there.

happens all the time.

in fact, heavier oil makes it easier. the oil gets into the breather because of too much oil, restricting airflow, then pressure builds in the dif because of the heat from the gears, it doesn't take long for that pressure to spew oil out the dif.

currie was having this problem a lot with their rockjock 60s because the way the housing was shaped the ring gear was slinging oil into the breather vent clogging it resulting in the same issue. they changed how the breather works and its no longer an issue.

WB9YZU · Dec 1, 2013

I didn't observe any ridges, just the afore mentioned pitting, which I removed with 600 grit.

Yup, brand new gears.
The reason I didn't replace the yoke wasn't because I'm cheap

, it's because it never leaked before. But then, I don't think I ever filled the axle up to the relocated fill point, just to the OEM fill point (used my pinkie to check level).

Not all Dana 30's use shims for preload. The LP D30's used a crush sleeve.

Edit: I just read Rockclimbers post.
Yoke: Yah, I'm thinking it wouldn't be a bad idea to do so, just don't have one in my pocket at the moment.
Thinking about the Currie issue you spoke of: The higher oil level is not that far from the breather hole... Light Bulb. I'm going to see about sucking out 4oz of gear oil and blowing out the breather line.

-Ron

markw · Dec 1, 2013

Yup, but we generally discourage their use. Most everyone around here goes to an HP housing, or a bigger axle.

MoparManiac · Dec 1, 2013

Is it weeping from the rubber part of the seal or around the edge?

I dealt with a D44 that would weep from pinion seals until I ran a small bead of rtv around the seal before tapping it in.

rockclimber · Dec 1, 2013

MoparManiac said:
Is it weeping from the rubber part of the seal or around the edge?

I dealt with a D44 that would weep from pinion seals until I ran a small bead of rtv around the seal before tapping it in.

fair point... the seal housing could be scarred. I would try this, if that doesn't work then a yoke, if that doesn't work... crush the whole jeep and start over.

Digger87xj · Dec 1, 2013

did you reuse the oil slinger behind the seal?

WB9YZU · Dec 2, 2013

Forgive me for requoting a few of my previous posts, but it may help answer some of the questions that came up after these posts.

WB9YZU said:
Forgot to mention that it is a LP D30, so at the SOLID's fill level, the pinion is completely submerged.

Since the seal is wet and the bottom of the pinion area is wet all the way to the bottom of the housing where it drips off, I figure it's coming from there.

WB9YZU said:
The reason I didn't replace the yoke wasn't because I'm cheap , it's because it never leaked before. But then, I don't think I ever filled the axle up to the relocated fill point, just to the OEM fill point (used my pinkie to check level).

-Ron

Digger87xj said:
did you reuse the oil slinger behind the seal?

Yes I did, but it's submerged - completely.

And the more I think of this, the more I am thinking that there is simply too much gear lube in there and that the SOLID brand cover is designed for the HP D30 in mind.

I went down to the local HF and purchased an inexpensive transfer pump. Then I sucked out enough gear oil to take it down to the middle of the SOLID logo (about 1.5" down from the hole. Taking a flashlight and looking in, the fluid is now 1/4" below the top of the carrier bearing. Still "overfull" by stock standards, but may give the pinion seal a breather from being completely submersed in gear oil.

-Ron

Annoying D30 pinion leak

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