diesel402004

Hi KRB,
No the needle bearings inside the spindle. Once you pull wheel, hub, caliper, etc. off you remove 5 or six bolts and can pull the spindle off the axle shaft. There are needle bearings there as seen in this thread. Wondering if anyone has seen these get dry and case spalling etc. It moves freely enough so hard to imagine it's the problem. I wish I could pinpoint the noise while it's in the air. Everything spins so freely by hand so it's hard to imagine a bearing that's making this much noise not causing some kind of binding

KRB

Oh yea. I had one side dry out years ago. Can't remember what made me check them though.

When you lift it are the wheels suspended? If so, that changes the drive line angle and could be the difference no?

diesel402004

No. Not changing the driveline angle as I'm putting jack stands on the rear axle and lifting the front by the pumpkin. I'm going to rip into the front hub/spindle and verify those needle bearings are fine. Otherwise, I guess I just keep listening and wondering

rrgrassi

Lifting by the front pumpkin does change the driving angle since it is not centered like the rear pumpkin. Put stands under the front as well.

Also, since there is no weight on the drive line, noise can disappear. Had that happen on my old nissan 4x4. I finally found the problem though. A bearing race was galled a bit.

diesel402004

Well...I actually was lifting it by the area a little to the drivers side of the pumpkin on the tube (in order to get it centered), but no matter I do agree with you that is exactly what it sounds like: a galled bearing race.

rrgrassi

They way I found it was by a bit of vibration with the wheels off the ground. It was the right rear outer bearing.

KRB

What about removing the front drive shaft to help isolate/eliminate?

Man you are a frustrating case...

diesel402004

Well after replacing just about everything that can be replaced while looking for this shudder issue (ignoring the spalled bearing noise when cold) I've had a couple of other ideas. The shudder started when I had a friend with tranny shop fix rear main leak. That has been the only time the flex plate was removed since all the other things that have been done: tranny, carrier bearing, u-joints, mounts, etc. I have isolated the shudder to be coming from the engine itself when revving at 1-15K in neutral. It's a seat of the pants kind of shudder (the engine is not visibly rocking in the engine bay but you can definitely feel it in the seat). Is it possible for the flex plate to cause this if it hasn't been installed in the same location? Every other repair has had marks made so the reinstall can be the same. Is the flex plate heavy enough to cause this? Thanks in advance.

D

Angry Johnny

No, the flex plate is neutral balanced. Does the crank dampener have a rubber mounted outer ring? I forget. It could be slipping which may also be causing your noise. Sounds like that can travel.

diesel402004

Thanks Angry. I remember removing it on my other rig when I fixed that rear main myself, and I didn't mark its local, and it didn't change any "feeling" in the driveability. Oh well, back to the drawing board. It's minor but the old "it wasn't there before" thing is what bugs me

diesel402004

Well, after replacing everything that I could, I decided to try one more time. I dropped the rear driveline and turned the splined segment 180 degrees (it can only go one way or the other because of wide channels). Put a half turn on the pinion nut, tightened the crossmember nuts and the tranny mounts as much as possible and bolted it back in. Success! the shudder when starting is reduced by 70% easily. Not sure how it got out of "phase" except when I had the carrier bearing replaced. Maybe the tech didn't mark the shafts and assembled it wrong? One more mystery solved! The other "noise" that I thought was the TC turned out to be the right front locking hub and I had an extra. Hope this helps others

mknittle

The needle bearings in the front axle I got for my conversion have a ton of slop so much I assume the needles rusted up and disintegrated.

diesel402004

Sorry to hear mark. I was glad to find mine nice and greasy. Now it's on to replacement door pins.

D

mknittle

Considering the price of the axle the fix is pretty cheapI will be in there when I do my king pins anyway.
Glad you found your problem.Vibrations can be a PITA to find