My car shakes when decelerated at high speed

I have a 2000 Mitsubishi Galant ES 2.4L with automatic transmission. It drives great below 60 mph. When driving > 60 mpg, the car will shake violently if I release the gas pedal to decelerate. It feels like a rough gear shift on a manual car.

I have my car checked by several mechanics, but none could identify the problem. It will be great if someone can give me some clue what might be wrong with it. Overall it is still a good car running at 30 mpg at 160k miles.

Many thanks,


It’s the rotors, replace them.


Thanks for the quick reply. But do you mind going into a little bit more detail? How does this happen? BTW, the brakes seem to work fine.

Thanks again,


When you use the brakes it creates heat, lots of it. It ends up in the rotor. The rotor then can warp due to the heat and then when you try to stop, the are shoved side to side by the warped rotor and you fell it in the brake.

Generally today we suggest replacing the rotors when you get new brake pads, since they rotors seem to last just over a set of pads.

Good Luck


I see what you mean. I think there is some misunderstanding that I didn’t explain the problem well. In the situation I describe, deceleration is not done by braking but by giving less gas. You have to keep giving gas to maintain a certain speed, and when you release the gas pedal the car decelerates. Thanks,


If you shift into neutral over 60 mph and brake is all fine? Are you up to date with regular maintenance?

I would suspect a bad drive axle.

It sounds more like an automatic transmission problem. Not fimilar With the type of transmission on the car, suggest taking to a transmission shop for a drive test. Some will offer this service free of charge.

My first guess would be the transmission. I would suspect that the transmission was dropping out of overdrive with the lockup converter dragging badly.