Rebuilt D30 with ARB questions

I just finished reinstalling my D30 that I took into a shop to get rebuilt with 4.88's and an ARB and yukon gears. It was a complete rebuild with a master install kit and I also had a TNT truss welded on.

When I popped it in 4x4 to go for a test drive the front end whines pretty bad when I am on the gas. There is no noise in 2wd. My transfercase is fine and never made this noise before the rebuild.

I have two questions. I don't have OBA just yet so I have the bulkhead fitting on the axle taped off. Is it ok to run it like this? It shouldn't be a problem since the locker only requires air pressure to lock. I confirmed that the locker isn't activated.

Second question, since the axle doesn't make noise in 2wd would it be ok to drive it 25 miles to the shop to have them take a look at it?

Thanks for any help.

I assume you have 4.88s in the rear as well? Otherwise, any "test drive" in 4WD would be folly. Yes, it should be fine taping off the ARB nozzle as a temporary measure to keep crud out. You should also be fine 2WD'ing it to the install shop to have them check it out. Stay off the freeway if at all possible, don't want to spool those new gears up to highway speeds before they're broken-in.

fubar XJ said:

I assume you have 4.88s in the rear as well? Otherwise, any "test drive" in 4WD would be folly. Yes, it should be fine taping off the ARB nozzle as a temporary measure to keep crud out. You should also be fine 2WD'ing it to the install shop to have them check it out. Stay off the freeway if at all possible, don't want to spool those new gears up to highway speeds before they're broken-in.

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Thanks for the reply. Yes, I forgot to mention that the rear was regeared to 4.88 as well. The rear was broken in before the front work was done.

Top speed would be about 55 in 2wd to get to the shop, that shouldn't be too fast right?

You will be fine in 2wd taking it back to the shop.

Does 80W90 work for the gear oil?

You test drove it without gear oil in the diffs?


Yes, 80/90 is fine. :sunshine:

fubar XJ said:

You test drove it without gear oil in the diffs?


Yes, 80/90 is fine. :sunshine:

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haha, Thanks again. It's full of 80/90. I checked it like 4 times because of the noise. I just wanted to make sure that oil would work.

I talked to the shop today and I'm taking it in tomorrow. I hope it's fixed soon, I miss the jeep!

Ok, so the shop thinks it's the pinion bearing making the noise. "It went bad somehow".

What are the chances the bearing was bad? The axle sat outside for about a month without gear oil and axle shafts. Could this have contributed or is it a problem with the install?

Who installed it for you? Will they warranty it? Take it back to them, tell them the pinion bearing was bad the very first time you ran it, have them replace/reinstall it under warranty. If they pull it apart and the pinion bearing is coivered in rust, tell them you have no idea how that happened. :dunno:

fubar XJ said:

Who installed it for you? Will they warranty it? Take it back to them, tell them the pinion bearing was bad the very first time you ran it, have them replace/reinstall it under warranty. If they pull it apart and the pinion bearing is coivered in rust, tell them you have no idea how that happened. :dunno:

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The shop I took it too is the one that did the install. He called me and said I might have to buy the bearing but he'd cover the labor. We are supposed to talk it over when I pick it up. Seems to me like I shouldn't have to buy a new bearing because they were brand new when installed.

I figured it wasn't a big deal to get oil in it and the axle shafts because when they did my rear I pulled the cover to put a ruff stuff cover and everything was covered with assembly lube.

Sounds like a bad place to have your gears installed at to me.

Take a quality picture of the pattern when he has the cover off (using actual marking compound)...I'm dying to see it.

Well, the took a look at it and even replaced the pinion bearings.

I started shaking things around to see and now that I drove it a little there is some play in the front output shaft of the transfercase...

I am not sure how it happened. I rebuilt it about 2 years ago. There was fluid in the case. (ATF fluid). I guess I will try and change a few bearings.