This is MY05 manual transmission Forester that I have owned since new. It now has 103,000 miles on it. I drive it long distances mostly on the highway for work travel.
About 2,500 miles ago the problem started. A very serious vibration, similar in sound and feel to driving over a rumble strip started (but not quite as harsh as a rumble strip). The entire vehicle shook like on a rumble strip and there was a loud rumble. The sound and vibration would change with the speed of the vehicle. I was going about 75 mph and slowed down to 45 as soon as it started and the rumble slowed down in time with the speed.
At first I thought it was a tire about to blow, or maybe something weird with the road surface. But I continued to drive and the road surface changed with no change to the vibration. Then after about three miles the noise and vibration suddenly stopped.
I went probably 500~800 miles with no more incidents. Then it happened again the same way. The vibration and noise came back, lasted 3~5 miles, and then vanished. Over the last 2,500 miles or so this has happened maybe another 8 or 10 times.
I know a lot about cars and I am stumped by this. A friend of mine is a master mechanic and he can’t think of what it would be either (though he has not looked at the car). I rotated the tires and tried to wiggle the wheels while they were off the ground to see if there was too much play in the bearings, but they seemed fine. I also inspected all the boots and they are all in good condition so the u-joints should be well protected still.
What do you folks think? The fact that a vibration this severe can be intermittent is the difficult part in my mind. I suspect wheel bearings, a universal joint, or a half shaft, but how on earth could any of those things be intermittent?
I want to fix this before I get stranded, but I’d like a better idea of what to replace before I start working. Thanks for any help.
craigr
About 2,500 miles ago the problem started. A very serious vibration, similar in sound and feel to driving over a rumble strip started (but not quite as harsh as a rumble strip). The entire vehicle shook like on a rumble strip and there was a loud rumble. The sound and vibration would change with the speed of the vehicle. I was going about 75 mph and slowed down to 45 as soon as it started and the rumble slowed down in time with the speed.
At first I thought it was a tire about to blow, or maybe something weird with the road surface. But I continued to drive and the road surface changed with no change to the vibration. Then after about three miles the noise and vibration suddenly stopped.
I went probably 500~800 miles with no more incidents. Then it happened again the same way. The vibration and noise came back, lasted 3~5 miles, and then vanished. Over the last 2,500 miles or so this has happened maybe another 8 or 10 times.
I know a lot about cars and I am stumped by this. A friend of mine is a master mechanic and he can’t think of what it would be either (though he has not looked at the car). I rotated the tires and tried to wiggle the wheels while they were off the ground to see if there was too much play in the bearings, but they seemed fine. I also inspected all the boots and they are all in good condition so the u-joints should be well protected still.
What do you folks think? The fact that a vibration this severe can be intermittent is the difficult part in my mind. I suspect wheel bearings, a universal joint, or a half shaft, but how on earth could any of those things be intermittent?
I want to fix this before I get stranded, but I’d like a better idea of what to replace before I start working. Thanks for any help.
craigr