2006 camry overdrive vibration

toyota
camry
vibration

#1

I first noticed a vibration in my 2006 Camry?s transmission one year ago after my wife and daughter drove from Minnesota to Boston and back. I believe that it?s related to overdrive or lock-up, which aren?t the same thing, are they? I demonstrated it for my favorite mechanic and for the Toyota transmission specialist, and they both said it’s normal, but I wouldn’t buy a car that did this, and it’s getting worse.

When the transmission should lock up for best economy, there is a constant-pitch vibration that varies in intensity with load. I estimate the pitch to be about 20Hz, sort of like driving over rumble strips at low speed, but not that intense. This occurs in the speed ranges of approximately 30-35mph and 40-52mph when the load is light. Accelerating hard causes it to shift out of this behavior, and turning off overdrive also avoids the problem. Toyota’s specialist said the vibration was because the engine RPMs are low at these speeds and the engine is lugging a little. But, the pitch is constant across the speed range, and here’s the really interesting part, it happens while decelerating. Two more observations: the vibration pulses at the rate of two to three seconds when accelerating slightly, and the tachometer moves very slightly along with the pulsations.

Toyota checked the transmission thoroughly, but didn’t drop the pan. The fluid color and level were OK, and the computer didn’t give any failure codes. So, I wasn?t getting anywhere with my arguments. I decided that I would have to let it get worse before I took it back, which it has. It now happens more often, vibrates with more intensity, and vibrates when decelerating.

Another thing the specialist told me is that the lock-up clutch is modulated at about 20Hz–hmmm.

The car has 75,000 miles, and is under the “Certified Used Car” warranty. I want to be sure that Toyota accepts responsibility for the problem before the warranty runs out, so I’m looking for help in proving that there is a problem.

Any thoughts?