Vibration

[jnj]

Hello all,
2 months ago I put on Kumho runflats to replace the very worn out Michelin Pilot Sports. Now, being a somewhat cheaper tire, I fully expected some additional road noise, but not the following.
Please help diagnose~
Since the new tires I have notices a very prominent vibration that appears to be coming from the rear. I have had the tires back to the store for re-balancing and to be sure they were not out of round. Even after leaving both times with perfectly (according to them) balaced tires, I still have the vibration and noise.
The noise sounds like thwump thwump and is more noticable on right hand corners as compared to left hand turns. Even going strait the noise and vibration continue. The tire dealer says it is not the tires. Not sure where to go from here. Very limited funds these days.
Regards~
Jeff

 

[gmjunkie]

Hello all,
2 months ago I put on Kumho runflats to replace the very worn out Michelin Pilot Sports. Now, being a somewhat cheaper tire, I fully expected some additional road noise, but not the following.
Please help diagnose~
Since the new tires I have notices a very prominent vibration that appears to be coming from the rear. I have had the tires back to the store for re-balancing and to be sure they were not out of round. Even after leaving both times with perfectly (according to them) balaced tires, I still have the vibration and noise.
The noise sounds like thwump thwump and is more noticable on right hand corners as compared to left hand turns. Even going strait the noise and vibration continue. The tire dealer says it is not the tires. Not sure where to go from here. Very limited funds these days.
Regards~
Jeff

Did they Road Force Balance them,or just a spin balance??
If they weren't balanced on a Hunter GSP 9700 with a technician that knows how to use it,they aren't balanced!

PS Depending the miles and ware pattern,you may have to have trued!

Hunter GSP9700 Wheel Vibration Control System Solves Wheel Vibration and Tire Pull Problems that Balancers and Aligners Can’t Fix

 

[jnj]

Just called America's Tire. The use the Hunter manhine, but not the "Roadmaster" series or the 9700.

 

[gmjunkie]

Just called America's Tire. The use the Hunter manhine, but not the "Roadmaster" series or the 9700.

Find somebody that has one and a Tech to go with it!!
First thing I do when I buy a Corvette for resale is take it and and have the tires Road Force Balanced!!It's saved me thousands chasing vibrations!
My Kumho ASX all seasons have right at 50,000 miles on them and still smooth as glass!!

 

[bucket]

Hello all,
2 months ago I put on Kumho runflats to replace the very worn out Michelin Pilot Sports. Now, being a somewhat cheaper tire, I fully expected some additional road noise, but not the following.
Please help diagnose~
Since the new tires I have notices a very prominent vibration that appears to be coming from the rear. I have had the tires back to the store for re-balancing and to be sure they were not out of round. Even after leaving both times with perfectly (according to them) balaced tires, I still have the vibration and noise.
The noise sounds like thwump thwump and is more noticable on right hand corners as compared to left hand turns. Even going strait the noise and vibration continue. The tire dealer says it is not the tires. Not sure where to go from here. Very limited funds these days.
Regards~
Jeff

...
then again..there might have been a maniac on the air wrench and tightened your lugs out of sequence and too tight causing slight warpage of the rotor

 

[fixvet]

Since it's more pronounced on a hard turn, you have the beginnings of a rear hub bearing going bad on you.

I've got 40,000 on my Kumho AXS's and they still run smooth as glass once they're warmed up. They'll be on 5yrs. this coming January, so I know the rubber is harder than when they were new, but I'll buy another set for sure.

As has been said above, go to a different balancer with the best stuff, the Hunter GSP 9700!

Good luck!

 

[jnj]

Looks like you were correct. Bad wheel bearing and hub.

 

[fixvet]

Looks like you were correct. Bad wheel bearing and hub.

It's a pretty easy DYI project if you have some tools. You can buy new or reman'd hubs online for a good price. Check all the vette aftermarket catalogs and websites....like Mid-Amer., Eckler's, Corvette America, etc.

Good luck.

 

[65-to-00]

Devil's advocate ....

The thing that gnaws at me with this ..... ;squint:

Wouldn't a bad bearing show up with the old Michelin Pilot tires too?

One of the simple things I was going to suggest ... and I know you can't run them this way .... would be to swap L to R .... and see if there is any change overall or with the different loading in turns.

And ...... every so often a defective tire sneaks through.

I've had my Kumho run flats up past a buck and .... well purty fast ... and they were nice and smooth.

 

[Toms007]

I think that the Hunter 9700 will identify those types of problems with tires, wheels etc. That is where the road force balance is way beyon the normal balance.