Shake, Rattle, and Roll

[GGott]

Hi Fellas, My W250 has an ongoing vibration (shake) problem. I'm running out of ideas, hope you can help. The shake starts around 45mph and continues upward. Happens whether in 4th, 5th, under throttle or off, and in nuetral coasting downhill. Doesn't seem to be rpm specific. Starting at the front: Tires are 1yr old, on straight rims, and even tire pressures. Brakes allround are good-new rotors, calipers don't hang up, good condition. Wheel bearings to spec. Upper kingpins new, lowers tight and good. All steering linkage tight and good, steering box tight to an uncracked frame, Borgeson. New motor-transmisson mounts, tight to spec. Exhaust tight and properly hung. Cross members (rivet and bolt) tight. Drive shaft, straight and runout in spec. I have one leaf added to re-arced front and rear springs to bring it to aprox. stock height, the rear hangers on the front springs show little end play. Ran the truck on a hoist to 40mph and no apparent wobble from rear axles. Any thoughts and ideas would be greatly appreciated.

 

[91W350]

I would rotate tires front to rear and try it. You may have one separating or a bad belt or sidewall. They are very hard to pick up on. You could do that and spin up the tires on the hoist again to see if it jumps around. That being eliminated, I would be out of ideas, given all you have checked. I take it the alignment is right on and the front tires are not scrubbing or cupping. Glen

 

[Ctallman]

Im asuming you checked u joints and carier bearing while checking the driveshaft isnt outta wack. Other than that ? Good luck

 

[JLEONARD]

I agree to rotate tires and see if that makes a difference... I've had several bent rims . . stock steelies. My vibrations were always at around 60 or so... and a mounting the tire on a straight rim and balanceing it has always corrected it.

good luck.

Jay

 

[GGott]

Thanks for the replies, The driveshaft is a one piece unit, and the tires are 265/75R-16 Bridgestone on Eagle alloys and show no signs of cupping or scrubbing. Question... Is caster on a w250 a consideration with the near stock ride height?... . Thanks again... . Greg