1991 Toyota Previa Vibration and Rear End Whine (video)

[Kurtanius21]

Hey Previa Gang.

I am stumped with this one. Here's what happened.

Very quickly, my van developed a vibration at 45+ MPH. It's a manual transmission 1991 model, 2WD. It doesn't feel like a wheel balance issue. Wheel balance makes the steering wheel vibrate clockwise to counterclockwise at high frequency. This sort of vibration is more like an up-down vibration and quiet a bit more violent. It is severe enough to cause the van windows to make an annoying rattling noise. The vibration began quite suddenly.

I don't think this is engine related. Putting the engine in neutral while coasting does not remedy the vibration. No acceleration or engine performance problems when in lower gears.

I also inspected all the suspension components. I Wiggled the all four wheels at the 3, 6, 9, and 12 o'clock positions. Felt no wheel wobble. I saw no torn boots at the rack, ball joints, etc. I also tried my hand at the drive shaft. I felt no play even when I rotated the drive-shaft (rear end airborne). Pushing up and down created no wobble or looseness.

I jacked up the rear end of the van so that I could try observing for vibrations when the front wheels are not moving. Hitting 45+MPH really didn't produce the same kind of vibrations I was hoping for. Though I did feel very small vibrations at 45mph+, but not at the same magnitude. But what I did find was a loud whining sound coming from the rear diff. Is this normal? Could the jack stands possibly dampen the vibrations? Should I try again with only the Jack? Would this be related to the vibration? Note, The engine goes off at 29 seconds.

https://www.youtube.com/watch?v=sfJo...ature=youtu.be

[zak99b5]

Have you moved the tires front to back to observe any changes? Or better yet, do you have a set of mounted snow tires you could swap on to compare?

[mountainhick]

Could also be bad rear wheel bearing.

[Kurtanius21]

Went to mechanic. Found the problem! image.jpg

[mountainhick]

Not surprised. Good you found that. Having a blow out at high speed sucks.