Cadillac Owners Forum banner
87K views 252 replies 57 participants last post by  derone 
#1 ·
2001 STS 34,000 miles

My 2001 STS has been back to dealer nine times for this 60-75 MPH Shake/Shimmy. Cadillac zone rep drove the car and said it is OK. This problem comes and goes. after having a tire store balance the tires it lasted 300 miles. Now time to balance again, this game is getting old. Went 300 miles without any problem, now Shake/Shimmy again.


Owned 92 STS and it drove perfect, no shake/shimmy. Also owned a 1997 Concourse, drove perfect too. What did Cadillac do to their front wheel drive. They have replaced the tires (1.5) sets, 6 balancings, front control bushings replaced. Cadillac customer care offered free tires and oil changes for two year. I said "No thanks I just want my car fixed. They said they would continue to work on it. I think Cadillac dealers need special hotels for owners of this Shimmy/Shake problem. They can balance at night while we sleep. The dealers are getting tired of seeing me as they have no solution.

How many thousand Cadillacs are out there that have a Shake/Shimmy problem.

Frank in Dallas texas
 
See less See more
#127 ·
Okay, the lower mount plates that I ordered, showed up yesterday. I immediately took them to the basement, and began work. The center hole is approximately 9/16". I bored out 6 plates, to about 1". I used a 3/4 step drill bit, and finished up with a Roto Zip with a grinding wheel. I installed them this evening (removed old plate and bolt, installed new bored plate on top of old plate, so not iw is double plated), and will update you tomorrow. So far, I can tell that the rubber bushings now have more stress on them. I put about 8 miles on the car after the install, but never got over 45 mph. It may be a placebo effect, but the car does feel a little more solid now. Anyway, I will know if this had any effect, good or bad, at about 6:45 am.

Don
 
#128 ·
have any of you had your hub assemblies aka "wheel bearings" replaced? I had a shimmy problem on my 94 eldo at 60-80 or so, i had one of them replaced and the problem vanished, same thing on my 97 regal. My 96 just started shimminin at 65-80 before and after new tires and rims off 06 sts. I recently got back to my pothole ridden hometown in wisconsin after being in arizona for a year with the 96 and after hitting a few potholes i believe one of my hub assemblies went again
 
#129 ·
Well, doing my little mod didn't help. The shimmying is still the same. The car does feel tighter though. Seems to wander less also. So it wasn't a complete waste. Next step, looking at the rear of the car. Last April, my car was rear ended. The bumper cover was damaged, and there are three clips that hold the center section up to the body, that had broken off. That caused the bumper cover to hang down a bit, in the center of the car. While driving it home from the accident scene, the car had the same vibration, only it was worse. So that is the next area I am going to look at. I am beginning to think that the rear bumper cover is working almost like a parachute, and causing the vibration. I'll let all know what happens.

Don
 
#132 ·
JimD said:
Dadillac or Logan or anyone else actively thinking about the original problem on '98+ Sevilles and 2000 - 2005 Devilles...

Any chance someone could fabricate a strut tower brace as a test????
I am actually considering it. But if I do this, it will not be until the summer, at earliest. In the meantime, I started hunting for aerodynamic issues. I am starting in the front of the car, and working backward. So far, to eliminate hood vibration, I adjusted the plastic adjusters upward. No change. Also, I removed the front hood seal (as it is kind of scoop shaped), and no change. I will be reinstalling that. I will continue to search. Although I will not rule out mechanical issues, I am opinionated that the real problem is aero.

Don
 
#134 ·
Dadillac said:
I am actually considering it. But if I do this, it will not be until the summer, at earliest. In the meantime, I started hunting for aerodynamic issues. I am starting in the front of the car, and working backward. So far, to eliminate hood vibration, I adjusted the plastic adjusters upward. No change. Also, I removed the front hood seal (as it is kind of scoop shaped), and no change. I will be reinstalling that. I will continue to search. Although I will not rule out mechanical issues, I am opinionated that the real problem is aero.

Don
your problem could be aero as i believe you said earlier that you had been rear ended, but i believe most everone elses problem has to be mechanical, as the car would have shimmied from the factory assuming nothing major has been done to the aerodynamics of the car
Also i would like to hear from anyone else that has replaced their hub assemblies "wheel bearings" as it did wonders for the shimmying on my cad and buick
 
#135 ·
There has been a commendable effort here to resolve this problem that has been quite informative and completely logical, which may be the main cause of these vibration issues, but I am going to throw another curve in here.

Just last Friday, I did my rear brakes. I bought brand new EBC sport rotors and AC Delco Dura Stop pads. (which now match what I have on the front brakes.) I do not feel any of the vibrations I had in the 70-78MPH range anymore.

It is possible that this vibration could return after my next tire rotation.

It is also possible that my cradle bushings are not to the point yet to where they are loose enough to cause vibration.
 
#136 ·
tstach

Before your brake job, were you experiencing the 60-75 mph shimmy/vibration? When driving over 75, did the shimmy disappear? While driving down the road, and the car was shimmying, did it just disappear, and reappear a short time after? This is the issue that we have. Not a constant vibration, that just keeps getting worse, the faster you drive. This is an annoying parasite that is sucking the bejesus out of me.

Don
 
#138 ·
tstach said:
Before the brake job, I had vibration from about 68MPH to about 78MPH. 80MPH and higher - no vibration.
Thanks. I was actually considering swapping in a good set of rotors anyway. I cheaped out and got a lesser brand. My brakes vibrate on occassion, and the rotors may have warped again. So, hopefully:angel: , when I get around to doing this, it will solve the shimmy issue.

Don
 
#139 ·
I ordered a strut brace this evening. It only cost $29.91 from www.gmpartsdirect.com. I was looking all over the web for a brace, but could not find one. Ends up there was one under my nose the entire time. Cadillac makes one, and it is on my parts list. I was going to make one myself, which I am sure, would have cost me more than $30.00. Once it is in, I will post how it helps, or doesn't help. I am not expecting any good report. but, if I don't do it, I will always be wondering.

Don
 
#142 ·
Logandiagnostic said:
Please explain your discovery....part #....application....etc. Limo/ heavy duty part?

Thanks...

Logan Diagnostic
www.ledfix.com
www.logandieselusa.com
www.airbagcrash.com
I don't know where Dadillac got his information, but this picture is an export (Japan) STS from another post somewhere on this forum. Notice it is 2000 model or later as the engine has COP ignition. According to the other post, the brace part# is 25653157.
 
#143 ·
Go to the Cadillac Tech Tips section of the forums. In there, at the top, is a sticky for '98-'04 parts list, that was posted my iametarq. Open it up, and open the link. When the pages load, look at page number 198. On the left side bottom, you will find the brace. I found this yesterday morning, and called a dealer. He was under the impression it was a support for the radiator. I kept looking at the pic all day, and know that this is the strut brace that is in those car pics. And at $30, I couldn't say no. It is worth a shot.

Don
 
#146 ·
Logan, I just checked my car, and it is 44". It seems that the Deville's are more cab-forward than the Seville's though. My brake reservoir is about even with the top strut nut. As long as the reservoir is lower than the strut towers, I do not see why it wouldn't work. Let me get mine first, and I will post how things are.

Don
 
#149 ·
El Dobro said:
Has anyone tried replacing the control arm bushings with aftermarket HD type ones? The original bushings were new for 1998 and are special in that they're designed to deflect the arm when hitting potholes, etc. to lessen the impact to the rest of the car.
Not sure what you mean. The stock control arm bushings are made of a soft rubber? If that is the case, then that could be a possible cause. Please elaborate. Also, if this is the case, does anyone make poly bushings for the arms? Energy Suspension maybe?

Don
 
#150 ·
Here's what it says in the 1998 Seville technical manual. "The control arms' front pivot bushings are rubber-hydraulic designs, which permit the use of a very low fore-and-aft rate without incurring undesireable vibrations. The soft rate in this direction permits the front wheel to move slightly rearward over bumps to minimize impact harshness. By aligning the control arms' rear pivot bushings with the front wheel centerline, they can be tuned more firmly to resist lateral forces, thereby providing sharp steering response. The front suspension's compression travel is 7 percent greater than the 1997 Seville".
 
#151 · (Edited)
Well.....somewhat back to square one.....2 weeks ago is was forced into a ditch by a near head on....

I was checking the front alignment today and the front toe was knocked way off....

Now need to get a tire rebalance etc....

Anyway, looked up the 2001 Eldorado today. It still uses the upper dog bones. The question is....is it also using the 2000 and newer Northstar block?

So the upper Eldo dog bones may also help the problem. The parts may bolt right onto the engine. It of course would have to be modified at the radiator support. But the dog bones and engine mounts may be a direct fit......at least maybe for the 2000 and newer block.



Logan Diagnostic
www.logandieselusa.com
www.ledfix.com
www.airbagcrash.com
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top