Car Owner Problem:

My wife’s 1993 Mazda 626 car has a strange vibration when you hit the speed of 60-65 mph. During this time, the car floorboard and dash panel basically shakes which makes driving very uncomfortable and scary. I took it for car front end alignment and everything checked OK. A new set of tires were also installed including one of the front driveshaft which was loose. Nothing seems to work and my wife is giving me fits. Can you help?

Car Tire Advisor:

Car vibration is usually a result of an unbalanced weight during rotation of any mass of matter or object. In your case, make sure it is not engine related by testing the problem when the car is parked on neutral with the engine rev up. It should not show any vibration otherwise, you have to check the engine and trany mounts for wear and looseness. If you are confident that the problem is happening only when the vehicle is moving, you can check the following:

Car tire balance, make sure they are all dynamically balanced using a tire balancer. I suspect you have done this already after you brought the vehicle for alignment. I am also assuming the alignment mechanic has checked the tires for side to side run-out to check if the front tire bearings are not worn.

The car front drive shafts on both ends of the trany should be checked for worn CV bearings and mountings. If you can raise the front end up and have the engine started with the trany in drive, you should see no sign of wobble on the drive shafts as the tire spins. You can also block each tire one a time and see if the wobble of the shaft will show. Use a wooden 4X4 about 5 feet long but make sure the vehicle is properly supported to avoid injury.

Notes:

When in doubt, bring your vehicle to authorized Mazda Car dealership to make sure your tire problem is fixed.