Originally Posted by
BillCarry
A while back hit a bad pothole. Broke right motor mount. Was on the road and had mount replaced. Still had vibration at idle. Took to a shop that sounded like it knew this kind of stuff. They replaced the left mount and the trans mount. Vibration got worse. They don't know what the problem is. I got under the motor home and looked at things, but nothing obvious to me. Could sure use some ideas.
Have you checked your serpentine belt system for unusual belt gyrations or wobbly pulleys? A hard jolt could have broken or cracked a mounting bracket for an accessory like the AC, pwr steering, alternator.....check the HB and crank pulley, as well as the fan for bent/missing blades. Anything out of balance can cause serious vibrations.
Last edited by rnash4; 10-16-2019 at 20:48.
Reason: add to post.
'95 GMC Sierra 6.5TD C2500, reg cab, long box, 2x4, 4L80E, 3.73 ratio, VIN F, L65, 120K. Mods: DE 4" exhaust/crossover, WW2, PMD relocate, Dmax fan/clutch, HP air filter, Fluidampr, B&M Trans/Diff covers.