mechanic is stumped.

Just bought my 2003 tacoma 4x4 v6 a couple weeks ago. Im getting a strange vibration, you can hear it also, under my feet in the floor boards and gas pedal when going down the road l. i called the dealership of coarse. they said it sounds like middle bearing or u joints. i brought it in the checked the U joints and bearings. all good. checked the fluids in the rear end and transfer case. all looks good. what could it be? Any Ideas??

 

If you can't tell what area the vibration comes from and you can feel it in the floor, chances are it the carrier bearring. I had one go out on my '98 years ago and it absolutely drove me nuts finding the problem.

As for inspecting the carrier bearring, it can't be done visiably. The rubber bushing that it lives in is designed to flex around a 1/4". When I took mine out I could not feel anything wrong with it, but since I had the new one, I put it in anyways. Vibration was gone after I changed it.

Curiosity got the better of me a bit later. I decided to cut the bearing apart with a grinder thin disk. You could see a very small section of the bearring race that lost some of its chrome coating. This could not be felt by rotating the intact bearring.

 

okay thanks a lot. so discouraging when the mechanic couldnt see an issue.