Found source of noise(hopefully)

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Nov 9, 2006
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Alpharetta GA
Well if anyone is familar with my few posts they will know I have been chasing a noise/vibration when decelerating and above 75mph for a while. I have changed rear u-joints, rear pinoin bearings and carrier bearings, front u-joints and serviced pretty much everything. My cruiser is still bone stock also. I changed the front u-joints last wednesday and headed to the redneck riveria thursday(about a 5 hour drive), and guess what, the noise was still there and got a good bit worse. I had a chance to pull the cruiser in the shop today and run it in the air and it sounds like when decelerating the rear drive shaft itself is coming APART! The noise is definetly what I hear when I'm coasting down a hill but it sounds like it is inside the shaft. I am going to call the local driveshaft shop tomorrow, but has anyone had any experience with a problem like that? Thanks as always!
 
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Well if anyone is familar with my few posts they will know I have been chasing a noise/vibration when decelerating and above 75mph for a while. I have changed rear u-joints, rear pinoin bearings and carrier bearings, front u-joints and serviced pretty much everything. My cruiser is still bone stock also. I changed the front u-joints last wednesday and headed to the redneck riveria thursday(about a 5 hour drive), and guess what, the noise was still there and got a good bit worse. I had a chance to pull the cruiser in the shop today and run it in the air and it sounds like when decelerating the rear drive shaft itself is coming APART! The noise is definetly what I hear when I'm coasting down a hill but it sounds like it is inside the shaft. I am going to call the local driveshaft shop tomorrow, but has anyone had any experience with a problem like that? Thanks as always!

If you have the center differential lock switch, you can remove the rear driveshaft, lock the center diff, and drive around to help you determine if it is actually the rear driveshaft causing the problem. In the meantime, I'm not really sure what you mean by the drive shaft sounds like it is coming apart.
 
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Dec 4, 2005
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Is the noise almost like when you hit the rumble strips on the side of the highway, only not as loud? Could it be worn splines in the slip yoke? That would probably cause a noise.
 
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Sounds just like the rumble strips on the hwy when decelerating. I'm pretty sure it is internal in the shaft because I crawled under it with another tech while it was running and a friend of mine was accelerating then letting off constantly and the noise was very loud from the middle of the shaft itself. Pretty weird huh? And yeah I don't have the center diff lock switch yet so I can't pull the shaft out and still drive it.
 
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I've got the same noise after my J spring lift. All was quiet before but now I have that very slight rumble when decel. No play in my U joints. I have pulled and cleaned the splines on the front shaft but not the rear yet. If you want a poor mans CDL switch just go to a junkyard and grab a toyota hazard switch. Mines from an old tercel and it works great! Let us know what you come up with so I can do it to my truck!
 
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You don't have to have a CLD to drive with the drive shaft off.
THe VC will kick in when you rev the motor up.
You may not want to run it like that very long but you can drive it that way to do your test.
 
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Alpharetta GA
Pulled the rear shaft, noise is gone!! The bad thing though is the driveshaft shop told me it probably wasn't the shaft but something in the rear diff or t-case being amplified by the shaft! Great huh. How bad is it to drive on the front end, I only live a few miles from work, would it be ok for a few days?
 
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Pulled the rear shaft, noise is gone!! The bad thing though is the driveshaft shop told me it probably wasn't the shaft but something in the rear diff or t-case being amplified by the shaft! Great huh. How bad is it to drive on the front end, I only live a few miles from work, would it be ok for a few days?

Other than slightly different handling, there is no issues with driving it in front wheel drive.
 
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Sep 23, 2004
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I suspect the pinion bearings. Crush collars suck and can cause these symptoms. Over time and even just moderate 'wheeling play can develop bewteen the inner and outter pinion bearings because of a crush collar. You should check the pre-load on the pinion bearing. In this case it's not so simple since you'll need to pull the diffs and the carrier out of the 3rd member to properly check the pre-load.

Especially when the truck is lifted and the pinion angle changes this thing shows up. If it's not due to a u-joint the next thing is pinion bearings and mostly likely it's backed off pre-load.

*Oh yeah, this was more in repsonse for Erratic, not tommy(I saw you changed bearings already)*
 
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The driveshaft shop just called. It was out of balance just a little but the main thing he found was that it was out of phase by about 30 degrees. He said that can definetly cause some noise so we will see. I should have it back in tonight.
 
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All I have to say is :mad: . Yeah, it's still there. The weird thing is when I rev it up in the air in 4 low I don't hear the noise when decelerating. In 4 hi it does it every time, so I don't know if it is something to do with the different speeds or it is internal in the case itself. It also makes a definite noise around the rear hub areas while running in the air but not too loud, that goes away when engaging the rear locker. So many different things it could still be. The drive seems to be lacking a little of the vibration it had before so that is ok I guess. Has anyone torn into their t-case for a problem like this. I think I recall someone saying they had a problem with their output bearing in the t-case. I still haven't changed the rear outer wheel bearings which looks fairly easily but I get the feeling thats not the problem. The best part is my wife is now aware of the noise from the long trip we took and calls it a piece of junk because of how many parts I have changed and it still isn't fixed :doh: . Still love the cruiser but this is making me crazy!:confused:
 
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All I have to say is :mad: . Yeah, it's still there. The weird thing is when I rev it up in the air in 4 low I don't hear the noise when decelerating. In 4 hi it does it every time, so I don't know if it is something to do with the different speeds or it is internal in the case itself. It also makes a definite noise around the rear hub areas while running in the air but not too loud, that goes away when engaging the rear locker. So many different things it could still be. The drive seems to be lacking a little of the vibration it had before so that is ok I guess. Has anyone torn into their t-case for a problem like this. I think I recall someone saying they had a problem with their output bearing in the t-case. I still haven't changed the rear outer wheel bearings which looks fairly easily but I get the feeling thats not the problem. The best part is my wife is now aware of the noise from the long trip we took and calls it a piece of junk because of how many parts I have changed and it still isn't fixed :doh: . Still love the cruiser but this is making me crazy!:confused:

There is a way to lock the center diff in 4H even without the button. Search, find it, drop the rear driveshaft, and drive around to isolate the noise.
 

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