Virbration

[Truenorth]

I have a 97 1500 with 119000 km that has a vibration that is intermittent( vibration / more of a bounce) at speeds from 75 kmph to 130 kmph. I have verified my U-joints they are good, flipped the drive shaft 90 degrees, moved my rear wheels to the front, replaced the oil in the front and rear diff as well as did a visual inspection, no sign of abnormal wear or metal filings. This problem does not seems to be getting worse but is very annoying.

At a loos on what to veridy

[tom.mcinerney]

If 4 wheel drive, grease splines on drive shaft(s).
Might try rebalance wheels, check shocks. The pitman arm is probably wearing, tie rod ends too...

[Truenorth]

The vibration or hop is only in the rear. Wheels have been rebalanced when they were moved from the front to the rear.

[rwpierce]

Do you have a two piece rear drive shaft? If so I would suspect the carrier bearing or slip joint splines wore out or bent driveshaft.

[Truenorth]

Single piece drive shaft...It looks like fibrglass with aluminum connection on each side for the u-joints.

[NH2112]

How about a bent axleshaft, or drum out of balance?

[Truenorth]

That was the next check but I need to bet the tool to measure run that....but this not be a problem that would be always there and not intermittent.

[tom.mcinerney]

Truenorth==The Helm manual has a good section with troubleshooting/diagnostic analysis.
I would try posting [first searching]in a few other forums here first, though:
1.) GM Light-trucks
2.) 6.2L Diesel
3.) 2500HD/3500 HD Trucks & Drivetrain
4.) 6.5L Turbo Diesel

[TeePee]

I had a similar vibration problem on my old Opel sedan. On the way home from work on a rainy day, the vibration was present until I ran thru standing water. The vibration stopped. Conclusion was the exhaust system was resonant at city speeds and also at certain highway speeds which I usually avoided. The vibration was never present at the beginning of the day or after the car was cooled to ambient temperature. When the system heated up, the metal was less rigid and rang (vibrated) like a bell at certain speeds. Try stiffening up the exhaust pipe with angle iron attached at many points with clamps or ?? or drive thru water, if that isn't too inconvenient. Adding weight to or stiffening a system changes the resonance of that system...be creative. If that is the problem, you might consider replacing the exhaust with thicker, heavier or more rigid pipe(s)(stainless?). Like you I checked everything from u-joints to balancing wheels. Please let me know what you find to be the problem as I have a curiosity about stuff like this. Good luck, TeePee. (Retired sr. vibration technician/analyst 19.5 years)

[ 07-06-2004, 09:02 AM: Message edited by: TeePee ]