Topic: Driveshaft vibs/ rear output bearing

[jrock]

I've been noticing my rear output getting a bit loose, over and over. I have tightened it at least 6 times and yet, after a few thousand miles, it loosens back up. It has just a bit of play in the flange but you can feel it in the cab when driving. I just had a new driveshaft built with a CV a little while back and it is right on.

I believe my rear Detroit is the problem. It has a bunch of play and every time I shift it kicks and hits.

I was wondering if it is worth replacing my output bearing or just to keep tightening the flange? 

[jrock [OP]]

Does anyone has input as to if the rear bearing would be causing this? If the rear main was wearing out, would it do this or would it do something else? Is it safe to keep torquing the output?

[superyota]

there isn't a crush sleave in the tcase, so if keeps loosening up after you tighten it, assuming your bending the lock tab over on the nut to lock it in place, i would say you have a bearing thats on its way it.  everything you told me a couple of weeks ago when i was in town about how your detroit was acting sounds normal.  the only time your going to get it to completely disenguage is by pushing in the clutch all the way around turns or putting it in neutral and roll through your turns.  as far as the kicking and popping when taking off, every now and then is normal, but not all the time.  I might be thinking of someone elses truck, but wasn't there something weird with the pinion bearing a while ago when you first put it in right before you went on your camping trip?

[jrock [OP]]

So I tightened it as best I could. 2ft breaker bar and my foot I got it to tighten maybe 1/16th of an inch. Vibs are still there and the flange still moves.

Should there be any backlash on the output flange? Should I hear the bearing when I turn the output by hand? I don't hear anything when driving.

[superyota]

you shouldn't have any play/slop in the shaft.  if its moving enough for you to see or feel it, i would say its the bearing.  i think i have one in bako.  i'll check when i get into town tomorrow, or go by the house tomorrow and grab it.  there is 2 tcases in the garage on the floor.  you're going to have to pull them apart to get the bearing.  even a better idea, go to the dealer and get a new one.  i'll see if i can get a part # for you. 

and before you do all this, make sure you don't have a bad cv, u joints, or slop in the splines.  that would all cause bad vibes.  i've never seen a bearing on the shaft go bad like that.  you usually end up breaking something before you get that much wear, then again, you do drive the thing everywhere so who knows. 

[jrock [OP]]

I have a spare bearing from my duals. I'll wait to talk with you on Friday night.

I think driving with 33s and 5.29s all over CA just finally wore it out with 250K miles. CV it tight, DS has no slop, rear joint is good.

[superyota]

What about the pinion bearing?

[jrock [OP]]

Didn't check yet. I thought we impacted it on there?

[superyota]

I thought the bearing had a rough spot in it you were worried about before your big trip?

[superyota]

thats why took along an extra third when you went, isn't it?

[jrock [OP]]

We thought the crush sleeve was bad. Probably is but I don't see any oil there anymore. I am getting oil out of the T case.