vibration at hwy speeds

[deadbeat]

This is an old thread, but, since it was brought back up, I put a 1 piece aluminum ds in my truck and it fixed my vibration altogether. Spent about 1200 on new tubes, u- joints , carrier bearings , balancing to no avail. When I removed the crossmember and put in the aluminum one all was well in that department and still is. I took the ds out of a newer model that was longer and had it cut down to 78-1/2 inches center to center. 3/4 ton will require a little bit longer one, there are pages that show how to measure it.

 

[GMCanada]

I have noticed this weird vibration in my recently acquired 1996 K1500 extended cab at speeds around 60-65 mph when in 4WD. I thought it was just from running at those speeds in 4WD, but after reading this post I am going to look into it further.

 

[Schurkey]

My '88 K1500 had a vibration. Failed trans/transfer case rubber mount. New rubber mount, vibration gone.

My '03 Trailblazer had vibration that was worst at about 74 mph. Failed rear U-joint, coupled to a rear driveshaft that had some bend in it. The driveshaft shop did their best to straighten the shaft, and then installed both U-joints. Problem totally fixed...for about two years.

Same vibration, same speed. First thing I did was to verify the rear u-joint again. It was good. I figured the driveshaft was bent again.

Shoved in a Treasure Yard rear driveshaft (after replacing the wiped-out rear U-joint) and the vibration is gone, again.

I noticed that the extended-length Trailblazers got a huge-diameter rear driveshaft, while the regular Trailblazer got an ordinary-sized shaft. I have problems again, I'm gonna have a big-diameter shaft cut-down to the length of the regular shaft.