I have a 2008 MMH with 88,000 miles. Gas milage is still good, 28.5 avg. But in the last week, I have been getting a vary bad vibration, the whole car shakes at speeds of 20 - 40 mph under acceleration. I have ruled out tire balance because it only does it under acceleration, and if I let up on the gas it instantly goes away. I am fortunate to do mostly highyway driving, so it has not made it in for a check-up yet. I do not notice the problem as much in ev mode, but it's tough to get the car under load at that speed without the gas engine kicking in, I am typically coasting or going down hill when in ev mode at this range of speed. Anyone experience this problem? I was thinking it could be a bad drive shaft to create this much vibration, or maybe it's time for new spark plugs and wires. Any help would be great, before I open the wallet.

TB

 

Vibration update: Bad news, I took the car to the dealership for a diagnostic. Bad drive drive shaft. The dealership wanted $800 + $100 + tax. I pulled the 2 pcs shaft, and had it rebalanced at a local auto pats store. They replaced a bad u-joint, and rebalanced the shaft for $120. So I Just got it back, and had some trouble with the front collar. It is filled with 6 large ball bearings which do not seem like they are setted correctly. I did some web research and found some helpful websites. Got it together, but I still have a bad vibration. Not as bad as before, but after driving the car for a week without the driveshaft, it is clear, I still have a problem. MY driveshaft doesn't feel solid. I think the ball bearings have come off the shaft again. Anyone ever replace the driveshaft, and have these issues?