Mystery vibration - where else to check???

[mlwilliams]

95 extended cab w/ 112K miles. Has a vibration that appears at 37 mph and over. Have balanced tires (2x), changed shocks, u-joints and hanger, repacked bearings, rear diff oil, checked ball joints and it's still there. Ideas on where to check? It seems speed dependent and doesn't change with different gears on the trans. Any ideas? I'm about out of things to check.

Thanks

[Marlin]

Have you gone through any water lately? I had sorta the same thing happen to me. I found that the water got on the drive shaft. Emptied about a quart or more of water. Once I did that, stopped having the vibration.
Marlin

[eracers999]

Did you balance the d shafts after u loint replace?? Was the u joints original?? If the truck originally had the liquid plastic holding the u joints in and you just go replace the joint you will have a vibration problem.
When the d shaft was manufactured it was centered up and the joints cemented in place to run tru. I personally have Never, been able to just replace the joint in one of these and not have a vibration. Balance is a must..

Good luck/Kent

[Govt issue]

It is not uncomon to see the rear drums out of round causing a vibration like out of balance wheels. The shoes may be good just need turing.

[tom.mcinerney]

When my trans reworked, did ujoints too. The master tech said that it was good to lube the splines in forward driveshaft...but if you pump the shaft full of grease, it can cause an imbalance, vibe.
The helm manual has a thorough treatment of troubleshooting vibes.

[mlwilliams]

Finally made a little progress. Had the drive shaft balanced and it reduced the vibration quite a bit. It is still there sometimes but now at least the truck is livable to drive. Now to wait for something else to go . . .