Shaking only after warm up

[axgutt]

1995 Legacy Wagon, automatic, with just shy of 300,000 miles. When you take it out on the interstate and crank it up to 70 or so, it's smooth as can be for about 15 - 20 minutes. Then the front end starts to shake pretty severely when applying some torque - i.e. going up a hill, or just working to maintain speed. Definitely shakes the steering wheel. As soon as you let off the gas the shaking stops. The tires are old (Michelins with about 130,000 miles - still not down to the wear bars yet), so I swapped the tires from my 1995 Legacy Sedan over, which only have about 7,000 miles on them. That didn't help, though the ride was smoother. 

 

I've done lots of searching through the forum and on the Internet in general, and haven't seen anything quite like this - i.e. it only shakes when it's been driving for a while. It seems like most people either have shaking or they don't. Any thoughts on what to check for?

 

Adam

[mikaleda]

Well a basic inspection of the front end would be a good place to start, jack up the front end and wiggle the tire top to bottom side to side,There should be little to no play. Check cvs bu grabbing the axle shaft and see if it will turn back and forth in the cup, again with the front off the ground, it shouldn't move at all. If that all checks out then I would suggest checking the motor/trany mounts out. Seems weird that it only does it when warm, that might suggest wheel bearings or c.v. so try checking it cold and then after it warms up and starts doing it again.

Edited April 29, 2013 by mikaleda

[Rooster2]

I would suspect a bad half shaft. Any clicking noise from the front end? I had a car that was like what you described. Drive it for a while, and the half shafts would act up.

 

Like Mikaleda, get the car up on a lift, and look at the half shaft boots, and suspension components for any "play."

 

Good to hear that your car is going strong at 300K+miles.