I had watched this thread back then too hoping for a solution... Been there, replaced all the same things, even inner tie-rods. Never found whats causing the vibration either.

Btw - I found THE site to find your local GSP9700 Road Force Balancers! I'm going to give this a try, hopefully this weekend.

http://www.gsp9700.com/pub/search/FindGSP9700.cfm

If you have the same problem start a new thread with your symptoms. We'll find a solution. Please don't dig an old thread up asking for the answer.

BTW - I had high speed vibration, and even low speed vibration. Mine was caused by my brakes (calipers) not releasing the rotors fully. Caused very bad mid to high speed vibration today especially. I replaced my front brake hoses tonight and hopefully that was the culprit.

The problem could be your lower control arm. Try having someone turn the car steering wheel while you listen for any clunking sound on either side of the car'* front end. Analyze the lower control arm for movement. You may have to replace the lower control arm.

I am fighting the same problem with my '95 Olds 88. vibes start at 55, mellow at about 70. come back at 75-80. 81-82 all the way to past a c-note on the speedo, no vibes. 55 and below, nothing. New; wheels, tires, motor and tranny mounts, front bearings, rotors, steering rack, outer tie rods, struts, ball joints. Even put the OEM 15'* back on it to see if the vibes went away, no luck. Alignment checked, on the the car balance done with no change. Trans and converter has less than 20k on them and was checked by two independant shops. Now, in talking with the old school gearheads at the alignment shop, we a leaning toward the driveshafts (193k on the OEM ones). They told me to steer away from remans and go new (extra $10 bucks per at O'Reillys cause they have seen too many remans not be right. The reason to suspect the shafts is there is no vibration till you drive the car about 10-20 miles and then it gradually will get worse. We suspect the cages are worn and when the grease warms up things get loose. The driveshafts are the only spinning component I have not replaced. Since they do not represent a major outlay of $$$$ for me, I am going to go new on both of them and see what happens. Not unlike you, I have toyed with getting rid of it but I am way to far into it to give up now. I plan on replace the shafts after the first of the month and hopefully the vibes will go away.

vibration at speed,now every body take note!
lift the car by jacking up under the drivers side control arm,take off the wheel.block rear wheels,get in the car or have a buddy,start and hold your left foot on the break,now put it in drive and slowly run it up to 60-75 or so and you`ll find the vib. is still there! it`* the inner cv joint! now how to fix this i`m still trying to figure it out.I will let every body know when and if I do.

oh by the way it`* not the cv joints it the shaft of the trans.

I just ran into someone at pep boys with a 2000 ssei and I asked if he has a vibration problem,he said i have been chasing one for a while and he asked if had the goodyears on it,i said yea..he said he had to replace his..hmm i have to to get rid of 2..RS-A'*

Hi,
[I] had the same vibration in my 04 bonneville and corrected it by drilling out a 3/4" washer to 1" and removing each cratle bolt at a time and slipping the washer into the rubber mount and putting the cover and bolt and tighened each of them with a impact wrench and what this does is tighens up the rubber grommets beteween the engine cratle and the frame.

Please note that 1" washers do not fit into the rubber grommet so thats why I drillled out 3/4" washer.

I paid $1.65 for the washers and had a 1" bit to drill them out. (cheap Fix)

Let me know what the results are because it drove me just about crazy.

Good Luck.

joe

tires were my problem,all good now