Humming sound that becomes noticeable at 32 mph

ALBY1A

MEMBER
2004 TOYOTA SIENNA
6 CYL
FWD
AUTOMATIC
80,000 MILES

Our van has a humming sound that becomes noticeable at 32 mph and increases in sound as you accelerate. The sound appears to be coming from the left front side of the vehicle. The Toyota dealer said it was the left front axle hub bearing. I ordered the left front axle hub bearing, front axle hub sub assembly, front axle hub nut, snap ring, and bearing dust deflector from Toyota and replaced all these items and torqued to specs. After replacing the humming sound is still present. Additionally the vehicle has new tires but to isolate even further I rotated all four tires and the sound is still present. Any ideas would be greatly appreciated.

2 Replies

CARADIODOC

MECHANIC
33,754 POSTS

It sounds like you have a final drive carrier bearing that is out in the transmission. This is not too common but it does happen. Raise the car front on jack stands and run it at 35 MPH then you see see where the noise is coming from the confirm the failure. You can also put your hand on the case to feel the vibration.

If so the transmission will need to be rebuilt FYI here is how it is removed. Here are diagram to help you remove the unit.

Check out the diagrams (below). Please let us know what you find.

Cheers, Caradiodoc

Images (Click to make bigger)