Question-------------------------
Followup To
Question -
Tom: I've owned this 1998 Riviera for a year and can't shake a high speed (over 60 mph) shimmy. I've bought a new set of tires, balanced them, new tie rod ends, new stabilizer bar, rotated the tires, had the rims checked, everything the local Goodyear shop recommended, and it's still there. Any suggestions?
Answer -
OK, do you feel the shimmy in the steering wheel or in your BUTT ?. This is a SERIOUS question as it helps to identify if the shimmy is in the front or rear of the vehicle.
When the shimmy is apparent lightly apply the emergency brake while maintaining your engine and road speed and tell me if the shimmy gets worse or not.
If the shimmy gets worse this would indicate a problem in the rear of the vehicle, probably brake components.
If the shimmy does not change at all, This would indicate front end problems, such as brake components and or suspension components.
Also if you apply the brakes of the vehicle at the time of the shimmy using your LEFT FOOT while maintaining your engine and road speed does the shimmy increase or remain the same ?.
Has there been ANY mechanical work performed on the vehicle within the last year and if so WHAT was done ?.
Have you tried swapping the front tires and wheels from the front to the back and the back to the front and does the shimmy change in any way ?.
If you are sitting at a stop sign and immediately shove the gas pedal to the floor to induce rapid acceleration is there any type of vibration felt ?.
Let me know.
autohelp
Tom:
Shimmy is felt more in the steering wheel, but the whole vehicle shakes so I feel it in the seat too. Here's another clue I should have given you earlier - the shimmy changes under load or torque. Stepping on the gas or letting off the gas changes the shimmy. at some speeds, letting off the gas makes it worse. At other speeds, giving it gas increases the shimmy. Possible CV joint problem?
Answers to your other questions:
1) Tough to put emergency brake on - its a foot pedal that you have to push all the way down to release, but I'll try.
2) I'll try the left foot-brake, right foot-gas technique. Brakes (rotors and pads)were done within last 8 months, but the shimmy is evident, even more pronounced, under braking (a recent phenomenon).
3) In addition to brakes, I've had a rear air-shock replaced, stabilizer bar on the front-end replaced, super-charger belt and pulleys replaced, and routine oil-changes, air filters, etc. in the last year. Shimmey was there before and after all of these repairs, but it varied in intensity. I've put 25,000 miles on it and the shimmey, sometimes better sometimes worse, has almost always been evident. I thought it was in the tires, but I just had all 4 replaced and ITS STILL THERE.
4) I rotated the tires many times and the shimmey seemed to change, sometimes better, sometimes worse, but never disappeared.
5) I'll try the rapid acceleration from a stop approach again, but I do not recall the vibration when I've tried it in the past. But I might have missed it because this thing lays rubber when you gun it from a stop. The shimmey has been pretty much a 60+ mph symptom.
Thanks for your help, Tom.
AnswerGet back to me on the other items. Your shimmy is most likely caused by a combination of inner/outer CV-Joint wear, Both front axle hub bearings and worn motor/transmission mounts.
Even SLIGHT wear in each component can add up to a lot of combination of wear from all these items, Thus casing your shimmy.
Perform a RUN-OUT test of the front brake rotors while hey are still ON the vehicle. I would NOT be surprised if your RUN-OUT is excessive.
autohelp
