vibration

[swamprocket]

I've recently been getting a bad vibration in my 94 4x4 pickup. It's the worst in 4th and 5th gear, but the vibration is actually less the more rpms in these gears. Vibration is probably the worst at 50 to 60 mph in 4th or 5th gear. The vibration is not noticable in gears 1st through 2nd and just a little in 3rd. There is no vibration when coasting in any gear. Vibration is the worst when accelerator is slightly depressed. I thought to begin with it had something to with the clutch because there seemed to be some rattling coming from the clutch and now it doesn't rattle anymore. The clutch itself has always worked fine. I have even driven the truck like this for over 500 miles at all speeds from 0 to 90 and its not getting worse. Sometimes the vibration actually lessens.
I have been thinking it could be anything from transmission fluid, clutch pedal, drive shaft, cv joints, u joints, or transfer case, but I don't think it has anything to do with the 4 wheel drive because that still works great. Put simply the truck drives great except for the vibration in 4 and 5. Help!

[Colotoyboy]

Im not an expert, but my 90' had vibrations from 55-60mph. I got some new BFG's and it stopped. It was just the worn cheap tires. Im not sure if thats what you have goin one though. good luck

[muddiver]

If the tires are good, I'd check the driveshaft for any dents,damage,ect. and the u-joints first.