I have a sever shimmy during hard braking

Loud Noise Unknown Origin - Ask the GM Technician - GM-Trucks.com

www.gm-trucks.com > ... > Ask the GM Technician

Jun 30, 2006 - 7 posts - ‎3 authors
I get a loud clunking, grinding noise while turning to the right only, and ... I moved the passenger side tire to the rear driver side just in case it ...

can bad wheel bearing/hub cause loud clunking noises?

www.jeepsunlimited.com/.../showthread.php?...loud-clunking-noises

Nov 12, 2009 - 14 posts - ‎6 authors
driving home, i noticed some metal clunking sounds coming from the front driversside. at ... hmmmm....if it's grinding, then probably a bearing.

Front Clunking sound when driving straight. - TDIClub Forums

forums.tdiclub.com > ... > VW MKIII-A3/B4 TDIs

Dec 21, 2011 - I have a sporadic clunking noise from the drivers side front end. '98 jetta ... If I try to coast it gets really louder and more pronounced. ... whirring orgrinding could be several things: wheel bearing, brake pads due to a caliper ...

Quick Guide to Diagnosing Differential & Driveline Noises ...

There are a number of different things that could cause that problem, a bad tire, a lower or upper control are bushing, a worn out inner or outer tire rod end l, a bad wheel bering. To figure out exactly where the problem is you need to visually and physically inspect each side of the suspension by having someone move the steering wheel back and forth while you observe both sides from underneath the front of the vehicle. From there you should be able to see what is moving when it shouldn't be or not moving when it should. Also inspect your brake rotors. You may simply need new rotors and brake pads.

This sounds like it could either be brakes or a wheel bearing going bad. You can check this by removing the rear wheel and inspecting the brakes making sure the caliper is mounted on tightly and brake rotor isn't showing uneven wear. Also be sure to check the brake pads to make sure that they are not worn down to the squealer tabs. Most new pads are roughly 3/8" -1/2"thick. and will start squealing if at about 1/8"-1/16" thick. If everything checks out fine then check the wheel bearing by simply jacking the wheel up off the ground and grabbing. Now try to move it side to side or up and down, it should have no play what so ever. And spin the wheel to listen for screeching or squealing, it should rotate smoothly with no abnormal noises.

Your problem is a bad CV axle and outer carrier bearing failure. The grinding is coming from brake rotor on that side due to the bearing failure. the brake rotor and bearing is causing the lock down. Do not attempt to drive or further damage will occur. Transmission is probably OK. Replace both sides (CV axels and Carrier bearings, 150,000 is time) Check brake components for damage and replace pads while you are there.

The rotors, caliper, pads are brakes, and won't cause shimmy, even if the rotors are running out, you will only feel it in the brake pedal.

Shimmy is usually bad tie rods or wheel bearings, bad hub. If you changed the rotors, then you already have jacked up the car, you need to jack it up and move the tire just as if it was turning left and right, it should NOT move, if it does, its the tie rods. Now normally if it moves Lt or Rt its tie rods, if there is play pulling it directly towards you and pushing it back its bearings hub. Pushing on top and bottom face of the tire and getting play is usually the ball joint. If you can't figure out which one it is have a tech check it and tell you, then do the work yourself if you have to.

Hello, The rear rotor has 2 sets of brakes on it. The other thing is to look for slight movement in the driveshaft when it clunks. Depending on the rearend, some have to have both rear wheels off the ground to turn each side. And of course the trans in Neutral.

With the rear wheel you have an Emergency brake and a drum brake inside the center of the Rotor.
The rear of the brake backing plate has a rubber plug which is covering the Star-wheel adjustment for those drum brakes. You can try to loosen the Star-wheel to disengage the Emergency brake shoes. You can try pulling the brake cables toward the cab, to loosen the cables.

If this does not help, your Emergency brake shoe probably rusted off the brake mount and is jammed inside the drum. The linings fall off the metal like banana skins. I can tell you that if the Emergency brakes are a State safety requirement, you need to consider new rotors because the drum portion is usually trashed with rust.

I hope my Solution is very helpful to you.

never, I've seen them rust off. and there should be no reason to move it for a break service.

if you have warped rotors and brake gently you may not feel the shimmy,but will if braking hard.i would fit new rotors and while the wheels were, off also adjust the wheel bearings, if needed.that way you have elliminated two of the most common causes of shimmy.

If it shimmies with the brakes applied, it's a rotor problem....but like you say, it shimmies just at a certain speed with no brakes applied, check tires for out-of-roundness. If they look ok, you are looking at a balance problem with the tires.

In absence of more information, this is usually an symptom of warped brake rotors. A rotor can build up enough heat in a hard stop to be bendable especially with the high hydrolic pressure a brake pad can bring to bear. Simply, If you keep the brake pedal depressed hard after a hard/long stop it can warp the rotor. (NOTE: at a hard stop, as soon as possible let the car creep forward a few inches at a time so the brake pad won't be on any one spot too long, plus keep light brake pressure --only enough to keep the car from rolling). The warped rotor causes the brake pad and caliper to float too far from the rotor and you won't feel the shimmy until you apply brakes. Under brake pedal pressure each time the wheel rotates under brake pressure the rotor and caliper will rapidly vibrate a few millimeters to each side giving the sensation of a shimmy in the sterring wheel. Most of the time this can be corrected by having the rotors resurfaced( aka Turned)

Out of balance or out of round tires can also cause a shimmy but should occur at a given speed range. Warpped rotor shimmy occurs during deceleration.