2003 GMC Savana 3500 Q&A
2003 GMC Savana 3500 Question: why does my van shake from the rear violently?
With "The faster you go the harder it shakes" it has to be a balance or run-out condition. One of those conditions I recently had to figure out had brake drums that were out of balance. Depending on how fast the vibration is it could be a driveshaft or U-joint problem. By paying close attention to the frequency of the vibration you can tell the difference because the driveshaft will be spinning about four times faster than the wheels are turning. The numbers work out to approx. ten pulses per second for a wheel/tire vibration at 60 mph and about forty times a second for a drive-shaft problem. - cardocIII
Good chance a universal joint is LOCKED UP!! Real good chance!!! - pushrod
Sounds like common cense has an easier answer than all the scientific mumbojumbow. Nice I could under stand that, but I think the questioner could understand the #2 answer. Just keep it simple, ATTA BOY. - ProfessorG