Help! vibration

[Terry H]

I have been working on a 96 vette with severe vibration at 30 to 35 mph and 60 to 65 mph have put on 3 sets of tires new shocks brake rotors and 4 wheel alignment,,driving at 60 car is vibrating make a u turn and shake is gone make another u turn and shake is back any ideas Terry

 

[Rob]

I have been working on a 96 vette with severe vibration at 30 to 35 mph and 60 to 65 mph have put on 3 sets of tires new shocks brake rotors and 4 wheel alignment,,driving at 60 car is vibrating make a u turn and shake is gone make another u turn and shake is back any ideas Terry

Moving from the Site Help and Feedback forum, to the C4 Tech Forum....

 

[Huskerman]

Motor mounts.....or u joints......maybe. Wheel bearings or tie rods.........Who is balancing the tires and how are they doing it....? Hope you find the source of the problem.....

 

[Terry H]

Motor mounts.....or u joints......maybe. Wheel bearings or tie rods.........Who is balancing the tires and how are they doing it....? Hope you find the source of the problem.....

u joints are new,,tires were road forced at dealership wheel bearings and tie rods good,,drive shaft and axles also balanced

 

[Huskerman]

Does your car have an auto or a manual.......?

 

[Hib Halverson]

In addition to the question on the trans type...has the car every been crashed bad enough that the frame was straightened or had a section replaced?

 

[hcbph]

Vibration

An additional question. Has the vibration always been there or is this something new. If new, what if anything was done to the car prior to the vibration started.

 

[Terry H]

Does your car have an auto or a manual.......?

it has a automatic trans.,,,,,,unknown if car was ever crashed or when it started

 

[Tuna]

Wheel hubs/bearings - check them.

 

[Terry H]

Wheel hubs/bearings - check them.

r.f. wheel bearing is new ,,all others ok with dial indicator

 

[Hib Halverson]

This one has my curiosity. There's been several people posting and a number of questions, to review–the components which have either been replaced or checked ok are....

3 sets of tires
set of shocks
drive shaft and axle shafts balanced
brake rotors replaced
four-wheel alignment
new joints
new tire rod ends
new RF bearing others ok by dial indicator

Have I got that right?

As I understand the OP the vibration only occurs in two speed ranges 30-35 mph and 60-65 mph. The vibration was termed "severe". At the peak of the vibration intensity can you hear as well as feel it? That is, can you hear parts of the car rattling during the vibration? Is the vibration high pitched, such as a buzzing, or low pitched such as a shudder or shake? Between 35 and 60 does the vibration go away or just get less intense? Does the vibration change under accel or braking?

The fact that it changes after u-turns is interesting.

Have you checked the rear powertrain mountings and the bolts which hold the C-beam to the trans and rear drive axle?

When the four wheel alignment was done did any wheel require a lot of shims or adjustment to get it to align?

Have you checked for any bent wheels?

Carefully inspect the chassis for any evidence of repair after collision damage and report back.

What kind of tires are on the car now. Are they the stock sizes?

If the car's suspension, chassis or brakes modified? If so, please give some details.

 

[Terry H]

Terry H

Ok,,tires are correct size,,,they are kuhmo's however we had firestones and goodyears on as well with no change,,i guess the vibration is more of a shake, the whole car shakes ,there are no sounds,,,no modifications to the car,,,it is a convertible,,also changed lube in rear end and added positraction additive,,
there is a slight amount of play in the bushings in the arms that support rear spindles but certainly doesn't seam to be enough to cause this problem,,making the u turn has really got us stumped,,supposedly the car was ok before new tires were put on and the only problem we had was one wheel nut on each front wheel was rounded off so we had to chistle them off we thought maybe that damaged the hubs so being that the r.f. Was the hardest to get off thats why r.f. Hub was replaced even though it was not loose or noisy nothing has changed i have heard there is a bolt on the end mount that wears but have not been able to find this,,any truth to this

 

[Huskerman]

Here is a long thread from the Guru about vibration.....

Vibration.... IS GONE!!!! [Forums - C4 Technical] - CorvetteGuruForum.com

 

[Terry H]

Here is a long thread from the Guru about vibration.....

Vibration.... IS GONE!!!! [Forums - C4 Technical] - CorvetteGuruForum.com

don't really understand your answer

 

[Huskerman]

I was just posting a thread about vibrations and how they finally got to a conclusion on what caused it.....we all know it can be a variety of things and I thought by going thru that you might find some answers. Didn't mean to confuse you.........

 

[Terry H]

Terry H

Still fighting a shake ,,anything new from you terry

 

[hcbph]

Ideas

I'm wondering if one or more of the U-Joints is bound up or isn't installed properly in mounting? If either, the particular item (driveshaft or half shafts) may be running out of round and set up for the vibration.

 

[Terry H]

Terry H

i'm wondering if one or more of the u-joints is bound up or isn't installed properly in mounting? If either, the particular item (driveshaft or half shafts) may be running out of round and set up for the vibration.

no problem with the shafts ,,,keep wondering about tires,,we have kumos on and have tried 2 michelins with 2 bf goodrich and seemed better but still had a slight shake at the same speeds any possibility the side walls are too stiff and we should have something softer to absorb the shake,,,,,,,,,,,,,terry

 

[WhalePirot]

the wheels are not bent or out of round?

No idea if it's front or rear or if it changes if you swap them?

 

[Terry H]

Terry

the wheels are not bent or out of round?

No idea if it's front or rear or if it changes if you swap them?

wheels are ok,,,did not swap them and unable to tell if its front or rear,,,what do you think about the kumos