"Pacing myself" build

Something has definitely given up the ghost, and after today's test, it's either the rear drive shaft or something in the rear end. I double checked the rear pinion angles and that is tits. Put the rear end up on jack stands and brought it up to speed. Vibes start to kick in at 45mph and get so bad it vibrates the rear view mirror and hard top glass. Something must have finally broke after my MNF trip with Tom, cause that is when the vibes got noticeably worse. I think I can rule out a bent axle or bad wheel bearing because when I ran it without the rear DS, no vibes.
 
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bobthetj03 said:
Something has definitely given up the ghost, and after today's test, it's either the rear drive shaft or something in the rear end. I double checked the rear pinion angles and that is tits. Put the rear end up on jack stands and brought it up to speed. Vibes start to kick in at 45mph and get so bad it vibrates the rear view mirror and hard top glass. Something must have finally broke after my MNF trip with Tom, cause that is when the vibes got noticeably worse. I think I can rule out a bent axle or bad wheel bearing because when I ran it without the rear DS, no vibes.
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What about a vibration induced from the engine? Balancer? Something out of wack (bearing) in the transmission?
 
Still tough to know for sure, but my mechanic at work was under the jeep when I had it on stands checking stuff out as I had it up to speed (do not try this at home kiddies), and he put his hand on the TC then on the diff, and the diff was definitely vibrating worse. Still could be the drive shaft too for all I know, though I can't see anything physically wrong with the DS after removing it and inspection.
 
Could something have gone haywire with the factory Traclok? Clutches blown up? Springs grew legs?
 
How does the Tracloc behave in coast? Could it be that something happens under load that doesn't when it is on the coast side of the gears, say, when the rear DS is removed?
 
2006TJ1 said:
How does the Tracloc behave in coast? Could it be that something happens under load that doesn't when it is on the coast side of the gears, say, when the rear DS is removed?
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Vibes stay the same under load and at coast. I've put it in neutral and coasted down the freeway in a down hill at 70mph, and with the engine idling while coasting the vibes are the same.
 
bobthetj03 said:
Vibes stay the same under load and at coast. I've put it in neutral and coasted down the freeway in a down hill at 70mph, and with the engine idling while coasting the vibes are the same.
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And this is with or without the rear DS.

Edit: I see what you're saying. So it has nothing to do with load/coast. If it doesn't happen with the rear DS removed I would think it has to be isolated to T case output, driveshaft, or maybe pinion yoke?
 
2006TJ1 said:
And this is with or without the rear DS.

Edit: I see what you're saying. So it has nothing to do with load/coast. If it doesn't happen with the rear DS removed I would think it has to be isolated to T case output, driveshaft, or maybe pinion yoke?
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No vibes without the rear DS, so yeah, that's pretty much what I'm narrowing it down to. The rear diff yoke is new btw. I've replaced all the yokes, among other things.
 
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bobthetj03 said:
Something has definitely given up the ghost, and after today's test, it's either the rear drive shaft or something in the rear end. I double checked the rear pinion angles and that is tits. Put the rear end up on jack stands and brought it up to speed. Vibes start to kick in at 45mph and get so bad it vibrates the rear view mirror and hard top glass. Something must have finally broke after my MNF trip with Tom, cause that is when the vibes got noticeably worse. I think I can rule out a bent axle or bad wheel bearing because when I ran it without the rear DS, no vibes.
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My transfer case switch went bad on that same run!
Now my blower motor took a crap ! Well at least it's not that cold out
 
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psrivats said:
You and I have cursed TJs.

FWIW - I called balance masters and had a long chat with them. They don't make the ring in the size I need for the rubicon rear driveline (the front driveline is 2" dia, and the rear is 1.90" dia). I bought the 2" they sell and it is sitting in my garage. If that size will work for you, PM me your address and I will ship it to you to try out. The ring is simply a thin rubber donut with what sounds like small ballbearings inside.

I am waiting to take my rig to Dave so that I can get some suspension work done and take another stab at the vibracrap. Dave has promised to check the gears very thoroughly. I am going to get a new rear driveline ... I think that's where my problem is. This should be happening soon ...
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Yeah, my rear DS is 1.90" also, but maybe I could build it up with vinyl tape or something to get it to clamp tight?
 
bobthetj03 said:
Yeah, my rear DS is 1.90" also, but maybe I could build it up with vinyl tape or something to get it to clamp tight?
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Not sure how good of an idea that would be ..

BTW - have you tried the hose clamp balancing trick at all yet? It was there in that giant PM conversation we had a while ago. If you can't find the link, let me know and I will find that video again. It's actually prescribed in the FSM as a hail mary for really troublesome drivelines. This is one way to do on-vehicle balancing. What the specialty driveline shop did for me is a more advanced version of this (they had some software and hardware tools to do this in a better controlled fashion). It made a difference for me.
 
psrivats said:
Not sure how good of an idea that would be ..

BTW - have you tried the hose clamp balancing trick at all yet? It was there in that giant PM conversation we had a while ago. If you can't find the link, let me know and I will find that video again. It's actually prescribed in the FSM as a hail mary for really troublesome drivelines. This is one way to do on-vehicle balancing. What the specialty driveline shop did for me is a more advanced version of this (they had some software and hardware tools to do this in a better controlled fashion). It made a difference for me.
Click to expand...

I recall seeing that video, but don't remember where it was.
 
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