Front End Shimmy
04-21-2003, 01:45 PM
#1
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Front End Shimmy
Finally got things together and took the C4 for a spin this weekend. First of all, I would like to take this time to personally thank all the "Listers" for the help and feedback while I was sorting out the car over the winter. Would have sold it without your help. While out for a spin I noticed a slight left-right shimmy when braking which can be felt in the steering wheel. I do not feel a pulse in the brake pedal (warped rotor). There are new tires on the car which have about 1000 miles on them. The car tracks beautifully at all speeds with no noticeable pulling left or right. Any suggestions on what to begin to check first.
Thanks again
Thanks again
04-21-2003, 10:30 PM
#2
IHI KING!
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My C-4 recently developed a shimmy. I had concluded it must be the front brake rotors. As I was installing them, I checked the wheel bearings which were tight. I also checked the tie rod and found my right side was loose. I retightened it. I then completed rotor installation. I'm happy to report the shimmy is gone as are the worn brake rotors.
My advise, jack up the car and shake the front wheel at 12 & 6 o'clock. If the wheel moves in the vertical then your wheel bearing is loose. Then shake the wheel at 3 & 9 o'clock. If it only wobbles only horizontally, then the tie rod or steering rack is loose. Note a loose wheel bearing will wobble in both directions. A loose tie rod or steering rack will only wobble at the 3 & 9 o'clock direction.
My advise, jack up the car and shake the front wheel at 12 & 6 o'clock. If the wheel moves in the vertical then your wheel bearing is loose. Then shake the wheel at 3 & 9 o'clock. If it only wobbles only horizontally, then the tie rod or steering rack is loose. Note a loose wheel bearing will wobble in both directions. A loose tie rod or steering rack will only wobble at the 3 & 9 o'clock direction.
04-28-2003, 11:40 AM
#4
Instructor
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Replaced front rotors with a set of Porsche crossed drilled I picked up awhile ago on eBay. Installed new pads while I was at it. Needless to say the front end shimmy is gone.
04-28-2003, 04:11 PM
#5
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I am afraid shaker 71 that I cannot agree with you. I had exactly the same problem and it was a worn steering arm. I have to concur exactly with Rob on this issue. I replaced the LH steering arm and the problem which only showed up under heavy braking was solved.
I agree that warped brake discs (as they are incorrectly called) can cause a shimmy as can many other things and just under brakes. The discs are below the mimimum thickness and wobble. They are not actually warped.
I like your troubleshooting guide as well Rob.
Ciao,
Adrian
911C4
I agree that warped brake discs (as they are incorrectly called) can cause a shimmy as can many other things and just under brakes. The discs are below the mimimum thickness and wobble. They are not actually warped.
I like your troubleshooting guide as well Rob.
Ciao,
Adrian
911C4
