2001 Chevy Suburaban 1500 4x4 Vibration 70MPH

[1500j]

2001 Suburaban 3.73 rear end towing package LT. No lift factory everything. Just put new tires on it as well. 212,000 miles.

 

Ive had a 70 MPH somewhat harmonic vibration that has been happening the past two months. Its comes on @ 65 peaks @ 70 and is gone by 74mph.

 

Ive done many things. I have had the rear U Joint replaced twice. Once by me and once after I took it to a driveshaft balance shop.

 

 

HERE IS WHAT IS INTERESTING!

 

If I take the rear driveshaft out plug the transfer case and run the Suburban as a Front Wheel Drive truck in 4x4 the vibration does not occur. It drives smooth as silk when in 4x4 with ONLY THE FRONT WHEELS PULLING the suburban.

 

Any guesses as to what it is???? Its killing me. I cannot figure it out.

 

I just had the driveshaft balanced and they put a new Spicer u joint in while they did it. They said the front one is in very good shape.

 

Thanks, Im new here so if this needs to be posted elsewhere. Let me know

 

 

[Doug_Scott]

When googling : "Extension Housing Bushing Vibration" I come up with several forums talking about replacing the bushing and that once done it cured some vibration issues.

 

Are the bushing for the 4x4 and the 2x4 suburbans the same? When I look it up I only see one part number and that part number sometimes has 2wd in the description.

 

AC DELCO Part Number shows up from what I can tell as: 24207915 or 24241501. I think its the same part just superseded. What I cannot tell is if they are the same in the 2wd and 4wd suburbans. It does not show the distinction.

 

 

Thanks

 

I do not know if they are the same or not. Would make sense that they were the same, but, that usually ends up meaning they will be different. I would take the VIN into the local dealer's parts counter and give them the VIN and ask for extension housing bushing. They will be able to get the correct part number, and then the correct part. You could also compare the numbers you found to the one they found.

[Doug_Scott]

The clunking is the yoke moving up and down in the tail shaft. Its clunking in that bushing.

 

Correct, as mentioned above, I've only replaced the rear UJoint on the driveshaft. The front one is still factory.

 

Ill probably just live with it unless I learn more about replacing that bushing. I think the bushing is cheap, it just getting it out of there.

 

I don't listen to the radio when I drive. So any vibration or squeak drives me nuts.

 

Nothing better than driving down the road in a smooth car/truck .

 

Thanks,

 

The hard part changing the bushing is trying to get new one in without damaging it. The bushings I have actually held and installed are not very thick. About 2 to 3 inches long and maybe 1/8 thick near as I can recall. That was a bushing out of either a 727 or 904LA TorqueFlite.

To install it I used an old slip yoke I had(I normally used it to plug off extension housing when removing the trans for service) by slipping old bushing on slip yoke, followed up by the new bushing. Then align new bushing with hole and press new bushing in. If you take a good look at it first, you maybe able to use the slip yoke with the new bushing on the yoke, then slide the yoke into the housing, and use that press out old bushing while it also installs new bushing. Pay attention to the area around the bushing in the housing, look for some form of a "stop" that prevents the bushing from going in too far or out too far. For this to work this way, you cannot have any form a stop or ledge or some other way of stopping bushing from moving in either direction.

[02suburbanZ71]

Another update today.

 

 

I had the feeling lately that the vibration was getting worse again. Im thinking its just in my head, but I crawled under there once again.

 

 

Grabbed the rear U-Joint and tried to move it around. It was moving. Like 30 thou back and forth in the yoke.

 

I took the driveshaft out of the way. Put an extra U joint in the Yoke and tightened it up. THE DARN STRAPS WERE NOT MAKING CONTACT.

 

The hold down straps were worn or stretched enough that they were not making enough contact with the U Joint.

 

I would mount it with the clips holding it centered and tighten it down. After 100 or so miles the bearing cups would rotate inside the strap letting making the location clips useless and allowing play.

 

 

SO for 6 dollars I fixed my problem. NEW STRAPS. WHY DIDNT I THINK OF THIS SOONER?

 

Probably never needed anything else.....

What straps for the u joint? Whats the GM PN?