I have a 1994 trooper...the problem is that when I drive my car past 40mph...the car will vibrate like crazy...what seems to be the cause...the mechanic doesnt' know what to do....thanks.

 

Have you looked at anything yet?

Virtually any rotating part can give you a vibration at speed. So I'm going to suggest you start there.

 

thanks. I'll have the mechanic look at it on monday.

 

Vibration can come from a variety of causes: loose ball joints, incorrect wheel alignment, and one thing I personally experienced before.. a protrusion in one of the tires. One tire had a bump probably due to over-inflation.

 

All the things mentioned by J^^ are true but would probably be visible long before forty miles an hour. It's probably a U-Joint.

 

thanks. do you think it could be the driveshaft also?

 

Okay,


If it turns or "rotates" it could be "the problem".

So, yes it could be the drive shaft, which, incidentily, is where the U-Joints are located.

If it has the Double Cardon joint (two piece rear driveline) then you will have a total of six U-Joints. The ones in the rear are the most likely culprits.

Although, I said that any part that rotates, could be causing your vibration, it is usually a bad U-Joint.
I don't know where you live but if you are near a Les Schwab, they will check them for free. Most tire shops will. A driveline shop will too.

 

Thank you so much. The problem is the U-joint. Surprisingly, it only cost me $120.00 to fix the problem. Now, I am driving in the freeway again.

 

That sounds a bit steep to me, you got them all changed at that time?

 

Sorry, I forgot to mention that we changed the driveshaft also, in additionto changing the cross joint/U-joint... :-)