Vbration - Please Help

[RV Guy]

I have a vibration in my’86 coupe that has 79,000 miles on it that I cannot find. It acts just like a tire that is out of balance. I can feel it all the time and it becomes stronger as the speed is increased. It’s really not very noticeable until you are above 60 mph. From there it gets stronger and it very noticeable at 75. It smoothes out some as you go a little faster. It has been this way for a little while and does not seem to be getting worse.

I first noticed it awhile back and I thought it was an out of balance tire. I was planning to get a new set of tires so I didn’t do anything then. After I got my new tires I noticed that the vibration was still there. I had the tires rebalanced but the vibration did not go away. I took it to another tire dealer and had the tires rebalanced again but the vibration is still there. A check showed that my lower ball joints were worn so I replaced them. My rear wheel bearings were loose so I replaced them also and while I was doing that I also replaced the u-joints on the half shafts.

What else could it be?

Thanks for you help.

 

[dogfish246]

Im not sure, but what about a driveshaft? Maybe you should check that?

 

[ARKvette02]

does it do it with RPMS or speed??? Is your car a Manual trans?

 

[G Winter]

Were the wheels checked to see if they are bent ?


Glenn

 

[RV Guy]

does it do it with RPMS or speed??? Is your car a Manual trans?

Automatic and it does it with speed.

 

[RV Guy]

Were the wheels checked to see if they are bent ?


Glenn

They haven't been checked yet. Would that show up as part of a balance? The tires have been balanced three times. Two different shops.
Thanks, Ron

 

[RV Guy]

Im not sure, but what about a driveshaft? Maybe you should check that?

I've thought about that and it seems tight. I think the u-joints there are OK.
Thanks, Ron

 

[Baldie88]

Try checking the inside of your wheels for a build up of grease and brake dust. I had a similar problem with my wheels and had them rebalanced several times. Finally someone said to check the inside of my wheels and there were gobs of grease and junk. Took a brush and some cleaner and cleaned them real good. Problem solved.

Can't say that is your problem but it's what solved mine. Hope you get it fixed because I know it's very irritating.

Ron
"Baldie88"

 

[TedC]

RV Guy, Did you have the wheels road forced balanced? If not, look for a shop that has a Hunter 9700, and the tech who knows how to use it. This is the best way you can isolate out any issues with the wheels or tires. I know you had them balanced several times, but nothing beats a road forced balance. On one of my daily drivers, I had new tires installed and balanced. Starting at 60 mph, you could feel a vibration. They balanced them again, same issue. Third time, I had them road forced balanced, and they are smooth as silk.

 

[RV Guy]

Thanks everybody for your ideas. I will be working through some things with it over the next few weeks and I will post what I find is the problem.
Ron

 

[LT4man]

One thing I have done with my Vette since it was new: every wheel is in the exact same position as when I picked it up from the dealer. Every time I have had a wheel off, I have marked exactly what position it was on the hub.

After you figure out what your problem is and you correct it, I would suggest you do what I have done. The wheel and tire assembly on a C4 is very large. Anything one can do to maintain wheel position on the vehicle helps tremendously.

WHILE YOU ARE DRIVING YOUR VIBRATION-FREE VETTE, PLEASE DO NOT FORGET TO SAVE THE !

 

[Hib Halverson]

If you don't find bent wheels or out-of-balance tires, start looking at the driveline as a vibration source.

 

[lex luther]

RV Guy:

I would still focus on tire balance. I had to take my vette to Discount 4 times before they were able to successfully balance the new Goodyears I purchased from them. Turned out the balancer had more than one program, and the program for "alloys" turned out to eradict the vibration at any speed. Prior to that, I was having the same symptoms as you. Might want to consider if everything else checks out.

 

[gmjunkie]

RV Guy, Did you have the wheels road forced balanced? If not, look for a shop that has a Hunter 9700, and the tech who knows how to use it. This is the best way you can isolate out any issues with the wheels or tires. I know you had them balanced several times, but nothing beats a road forced balance. On one of my daily drivers, I had new tires installed and balanced. Starting at 60 mph, you could feel a vibration. They balanced them again, same issue. Third time, I had them road forced balanced, and they are smooth as silk.

Your Suspension and Alignment will Love you for it,Not to mention your Kidneys!!

 

[Paul Higg]

Junk, you da MAN!

 

[John Robinson]

Similiar problem

I have a vibaration also that is speed sensitive. Here is what I have tried and discovered. I tried putting the brakes on while coasting down in speed (that is when it is the nosiest) and the sound gets quieter. In fact if I really jump into the brakes it will go away for a while then as I cruise along it comes back and gets progressively louder. What I have discovered is that the rear brake pins and bushings are worn and the caliper is moving up and down on the pin. I have found replacement pins and bushings at Advance auto parts there number is 5059 when the finances get a little healthier I will pick up two sets of these parts and get rid of the noise (I hope) .

At least as long as I know what it is I am not worried about driving the car and hearing that noise besides the volume knob on the radio gets rid of a lot of the noise.

 

[RV Guy]

I have a vibaration also that is speed sensitive. Here is what I have tried and discovered. I tried putting the brakes on while coasting down in speed (that is when it is the nosiest) and the sound gets quieter. In fact if I really jump into the brakes it will go away for a while then as I cruise along it comes back and gets progressively louder. What I have discovered is that the rear brake pins and bushings are worn and the caliper is moving up and down on the pin. I have found replacement pins and bushings at Advance auto parts there number is 5059 when the finances get a little healthier I will pick up two sets of these parts and get rid of the noise (I hope) .

At least as long as I know what it is I am not worried about driving the car and hearing that noise besides the volume knob on the radio gets rid of a lot of the noise.

Glad you found your source of the noise. Mine is not noise but a vibration that shakes the car.

 

[killain]

I had the same vibration in my C-4 when I bought it, turned out to be one of the half/shafts, their made out of Aluminum and are easy to bend if someone has jacked the car up with the jack under one of the halfshafts ?

 

[RV Guy]

Problem solved

I have a vibration in my’86 coupe that has 79,000 miles on it that I cannot find. It acts just like a tire that is out of balance. I can feel it all the time and it becomes stronger as the speed is increased. It’s really not very noticeable until you are above 60 mph. From there it gets stronger and it very noticeable at 75. It smoothes out some as you go a little faster. It has been this way for a little while and does not seem to be getting worse.

I first noticed it awhile back and I thought it was an out of balance tire. I was planning to get a new set of tires so I didn’t do anything then. After I got my new tires I noticed that the vibration was still there. I had the tires rebalanced but the vibration did not go away. I took it to another tire dealer and had the tires rebalanced again but the vibration is still there. A check showed that my lower ball joints were worn so I replaced them. My rear wheel bearings were loose so I replaced them also and while I was doing that I also replaced the u-joints on the half shafts.

What else could it be?

Thanks for you help.

I promised to let you know the solution to my problem. Today I had the tires balanced on a road force machine - problem solved.
Thanks everybody

 

[Schrade]

I went through several sets of tires for a delivery fleet I used to own. Always went with E-load range high quality rubber. One time, one set of 5 Michelins had 2 tires that were so out of balance, it took double digit lead to balance them. One was later determined to be so out-of-round, it looked like a chicken laid it.

I did 4 nights @ 425 miles/night with that set on my own 1-ton. ---> hnoes