Vibration On Highway

remy's2000 · November 17, 2007

Hi there...

I have a 2000 GMC sierra 4.8, 5 speed manual 4x4 standard cab short box. The problem I am having is on the highway mainly, I am getting a vibration that I can feel in the shifter. I had the tires checked for balance with no change in the vibration. What is weird is that the vibration happens at lower speeds and higher speed, but become more noticable at higher speed. The vibration intensity comes and goes. My thoughts were maybe the driveshaft needs balanced. I unbolted the driveshaft down by the rearend and rotated it 180 degrees to see if that made a difference, but the vibration is still the same. I am a little puzzled and any advice that you could throw my way would greatly be appreciated.

Thanks!!

Remy

papastoy · November 17, 2007

How many miles do you have on the truck? Sounds like it might be the ujoints. Take the driveshaft off and move the joints back and forth. If you feel any binding or feel rough when you move them, they need replacing.

remy's2000 · November 19, 2007

Thanks for your response.

I did pull the driveshaft and both ujoints are tight and one of them is actully new. Is it possible the place that installed the new ujoint bent the driveshaft upon removal of the old one. I know they were beating on the driveshaft to loosen it. It was the ujoint closest to the transmission. I should have known better than to leave it there. That's another story. It has been almost a year since they replaced it. They told me they had trouble getting the old one out. The thing is I don't remember if the vibration started before or after the new u joint was installed, so I can't blame them. I just want to figure out what is causing the vibration. I have learned alot reading other peoples posts here and thought someone else might have had the same problem. Oh and my truck only has 75,000 miles.

Thanks!

Remy

Ranger · November 19, 2007

Have you checked the suspension alignment?

remy's2000 · April 27, 2008

It has been aligned and tracks straight down the road. I did have the problem with the ABS activating and not stopping the truck. And in panic I used the parking brake to stop me. There was a loud bang in the backend but atleast I stopped before getting t-boned. The parking brake still works, but engages all the way to the floor. I can't see how this could cause a vibration, but who knows... I have no play in the front wheel bearings. i am hoping when I get the driveshaft tested for balance it will cure it, but wanted some opinions before I spend the cash on that.

Any thoughts?

Thanks,

Remy

pennzoil29 · April 27, 2008

Thanks for your response.

I did pull the driveshaft and both ujoints are tight and one of them is actully new. Is it possible the place that installed the new ujoint bent the driveshaft upon removal of the old one. I know they were beating on the driveshaft to loosen it. It was the ujoint closest to the transmission. I should have known better than to leave it there. That's another story. It has been almost a year since they replaced it. They told me they had trouble getting the old one out. The thing is I don't remember if the vibration started before or after the new u joint was installed, so I can't blame them. I just want to figure out what is causing the vibration. I have learned alot reading other peoples posts here and thought someone else might have had the same problem. Oh and my truck only has 75,000 miles.

Thanks!

Remy

just a thought. they may have installed the wrong u-joint. I had an older 3/4 ton truck that took 2 different sizes. They installed them ass backwards, and the thing shook the hell out of me.

Zembonez · April 27, 2008

The problem does sound like a driveshaft vibration. You didn't mention how severe it was but some vibration through the shifter is pretty normal. All manual shift trucks rattle around a bit when the shifter isn't being touched. It's your truck so you should know if it has gotten worse...

A pretty inexpensive fix would be 2 new OEM u-joints and have the driveshaft balanced by a local driveline shop. It can make a world of difference.

remy's2000 · April 27, 2008

thanks for the advice!!

Today I pulled the driveshaft off and installed a new u joint and took it for a quick ride. This seems to have solved the problem, I will try a highway run later this week to see if it has cured the vibration. The u joint I took off seem to have a "flat spot" in it. The vibration was minor, but I try to keep things running smooth.

Thanks again for the comments!!

Remy