fullmann

I recently developed a weird noise under my truck, so I took it in for a look. They got it airborne and determined that the noise was coming from the driveshaft. When they pulled the driveshaft and sent it to the driveshaft place, they stated that all looked well, it just needed grease. So they greased it up and reinstalled.

When they had it up in the air, they pointed out the leaking right rear wheel seal, I knew it was leaking so I told them to fix it, and obviously rear brakes at the same time.

When I pick it up, The original noise is now gone, so that makes me happy. But now the truck has developed a vibration. The vibration only manifests at between 35-45 mph. But only after coming down from speed (60-ish mph), never from a stop, and it hasn't shown up when slowing from only 50 mph. Other than the frequency of the vibration changing between the 35-45 mph, the use of brakes or engine braking has no effect on the vibration. But after the truck shakes, the brakes have a pretty bad pulsation, not in the pedal, almost like a really slow ABS.

When the vibration occurs, I can speed up to about 50 or slow to about 30 to make it stop completely. The vibration is completely unpredictable. Although it does seem to be more inducable when the brakes and drivetrain are warm or hot. The only feel I get that tells me the vibration is about to occur is a slight sound that resembles the buffeting when you roll only the rear windows down.

Hopefully someone here has some input. I've already had the tires balanced/rotated with no change. The driveshaft has been re-indexed, and re-re-indexed, no effect. Braking is strong, no pulling any specific way. Although it feels like the brakes may be ever so slightly binding as it will hold at stop lights, with no brake pedal being pressed, on inclines that used to make it roll slightly.

Specs on the truck-- 00 4runner sport 4x4, 5speed, 197k miles, supercharged 3.4, 3" toytec lift, 285-75/16 tires on factory wheels, tundra upgrade front brakes with brembo slotted rotors.

The vibration was NOT present at all before the work was done.

thefatkid

It sounds like the rear shoes are over adjusted. jack up the rear of the vehicle and see if you can spin the wheels by hand. Not sure how that could cause an abs feel on occasion. It would cause a pulsation after a bit due to heat in the rear drums due to drag.

The rear ABS rotor could have been damaged possibly causing your ABS to activate. It is removed during the bearing replacement

kawicowboy

Im thinking drive shaft, whenever you remove the drive shaft it should be marked so as to put it back in the same location, it has weights on it. I would crawl under it and remove the shaft at the diff and turn it to the next set of holes and try it out and so on till the vibration stops.

fullmann

driveshaft has been tried at every different alignment. the vibration has not changed. so now its back at the original marked alignment.

I just took it out for a spin, and I couldnt induce the vibration. I did notice that the right rear brake drum was VERY hot to the touch, the left was just warm. I think it may be shoes too tight. so maybe tomorrow I'll get them apart and see whats going on there.

when I said it was an ABS feel, that was probably a poor choice of descriptives. its more of a pulsating feel. not activated ABS. like a VERY warped rotor.

DRCOFFEE

Rear axle seal leak. One of two issues. The axle seal is still leaking or the brake drum is out of round and needs to be trued up on the lathe from the previous axle leak.