Greetings,

I own a 2008 tC with ~44k miles. My hand brake got a little slack so I tightened the star adjusters on both driver and passenger sides. The instructions I referenced said to tighten the adjustment until the rotor locks, then back off until the rotor turns, then back off 2 additional clicks.

Everything seemed fine for several months. (Balance and alignment have been solid for 8 years.) Then I noticed a slight vibration at or around the rear passenger wheel. The inside tread was also slightly worn and slightly cupped.

I found a tC tech manual and learned that Toyota advises backing off the star adjustment 8 clicks. I readjusted my hand brake accordingly. I also seated the brake shoes by engaging the hand brake @ 30mph for one quarter mile.

I still have the slight vibration. My tires are bi-directional so I rotated the rear wheels only. Vibration persists. (It appears wheel balance isn't the culprit.) Now I'm wondering if my initial hand brake adjustment warped the top hat.

Here's the mystery. Applying the hand brake at 30 mph does not increase the vibration, nor can I feel vibration in the hand brake handle. Correct me if I'm wrong but this suggests the top hat isn't warped.

My only experience with a bad wheel bearing involved my old Chevelle. It produced a whine at highway speed but there was no vibration. Now I have a mysterious vibration but no familiar whine from a dry wheel bearing.

Thanks in advance for any idea(s) to locate the vibration.

 

Try to rotate the rear wheels to the front to make certain it's not a wheel or tire issue. Sometimes side to side is hard to tell, especially in the rear of a FWD car. Also, jack up the rear of your car, then grab each rear tire and try to twist/rock it from side to side (like you are trying to steer it) as well as up and down. There should be zero movement. Any movement is a sign of a bad bearing. There are plenty of videos on youtube for doing this.

If that checks out, next would be your alignment, but you want to make sure that there isn't another underlying issue that's cause it to be out first (worn bushing, bent control arm, etc.)

 

Thanks for the info. I'll get to it and post the results.

 

Ok, just rotated all 4 wheels. No side-to-side or up-down movement on the rear passenger wheel. Far as I can tell, bearing seems ok.

I test drove the car, half expecting the vibration to transfer to the front. No such luck. The steering wheel does not vibrate at all.

The original vibration is still apparent (although not as noticeable as when paired with the the slightly cupped tire.)

I'll take a look underneath for bent suspension part(s) and while I'm at it, torque any loose chassis nuts.

*********

When I first adjusted the hand brake a couple months ago, I can't recall whether I matched the runout correctly. Could incorrect runout cause a vibration?

 

same thing here, but after changing rear wheel assembly, it went away, are your rear wheel bearing assembly, original, or have you changed them like I did

 

here is a video to replace Rear wheel bearing hub: