2004 Rear Suspension Vibration

My '04 SR5 TRD Tundra has a vibration when braking between 40 and 60 MPH. The rear drums were just replaced and the new tires balanced by a Toyota dealership. If I brake hard, there is minimal to no vibration. This vibration is kind of like a shutter. What are some other things this could be?

 

Shocks?

 

Oh, sorry, I forgot...I just replaced the rear shocks too with stiffer Gabriel off road shocks.

 

Also, the truck only has 123K on it.

 

Do you feel the shudder in the steering wheel? Pedal? Or whole truck shakes?

 

When you say that the rear drums were replaced, is it safe to assume that they were replaced trying to solve this issue? And didn’t make a diference?

I’ll suggest checking for a bent axle shaft with a dial indicator, and checking that all the spring u-bolts are tight.

 

Not in steering wheel and not in the pedal. The back of the truck is shuttering, kind up and down . I also tried the e-brake test. Go real slow and only put the e-brake on (slowly) until the truck stops. No pulsing at all. Oh, ya, I just did a complete rear and front brake job too.

 

Would worn bushings in the leaf springs or worn out springs cause this? Bent axle...wouldn't this show up in a 4 wheel alignment? I just had the truck aligned at Toyota too.

I have been replacing the simple things to solve this, yes I started with brakes and shocks.

 

No, a bent axle shaft on a semi-floating axle won’t show up on an alignment, unlike a bent axle housing. Might be a long shot, but an easy check.

And yeah, have a good look at the rear spring bushings.

 

Thanks, I will check both the axle shaft run-out and bushings.

One question, wouldn't a bent axle shaft show up in regular driving just as much or even more? The truck drives (when not braking) real smooth.