Tire Balancing

wanab5150 · #1 (**permalink**) 08-01-2017, 03:51 PM

As far as the ball joints go I just installed a Poly windshield from Cobra Valley and I talked to him about the issue. He stated the ball joints cure the last little bit of turning ease and slight shimmy.......very slight. I asked specifically if I should swap out mine for his and he said NOT YET. Get the balance or whatever issue you have going on fixed then if you want the best FEEL, change them out. He said they're not a cure all...just an improvement. Also the fact that for 30K miles it was flawless then the next day with new tires it went to crap...that's not ball joints.

More on the Poly windshield from Cobra Valley in a post this week. I do have to say that I did not think I would be this happy with the clarity as I assumed it would be different than glass. I WAS WRONG! It's amazing!

OK.... So far today I removed the shocks and manipulated the A-arm up and down without a load feeling for any grit or stiffness. NADA! Smooth as glass. I also put the wheels and shocks back on and checked the ball joints for smoothness the old fashioned way with a long steel bar under the tire lifting up. No play on the joint and no gritty feel or stiction. None of that grabby sensation you read about some people having.

With my dial indicator I checked runout on 4 different places on every hub..... The brake caliper hub, outer stud flange edge, outer stud flange end, and the outside edge of the studs while rotating the assembly. One stud was out .015 from the others. I re-torqued it (and maybe hit it with a hammer in the process) but it's within .005 now. All four wheel stud flanges were within .008 at the worst. I am surprised they would be that close. Additionally, I put the dial on the tire bead and spun the tire and it was absolutely perfect on all four tires. I couldn't measure it because the dial would hit bumps on the bead but visually on the pointer I couldn't see ANY movement. So the wheels and tires are spinning round and true at least on the sidewall and the only out of round seems to be in the middle of the tire. But at this point no one seems to have a "to much" out of round spec. Not my dealer...America's Tire... or even Nitto when I called them.

Tomorrow I'm going to spin up fronts and rear on the car and see if I get a vibration.....I'm running out of ideas.

Cobra #3170 · #2 (**permalink**) 08-01-2017, 04:22 PM

Quote:

Originally Posted by wanab5150

As far as the ball joints go I just installed a Poly windshield from Cobra Valley and I talked to him about the issue. He stated the ball joints cure the last little bit of turning ease and slight shimmy.......very slight. I asked specifically if I should swap out mine for his and he said NOT YET. Get the balance or whatever issue you have going on fixed then if you want the best FEEL, change them out. He said they're not a cure all...just an improvement. Also the fact that for 30K miles it was flawless then the next day with new tires it went to crap...that's not ball joints.

More on the Poly windshield from Cobra Valley in a post this week. I do have to say that I did not think I would be this happy with the clarity as I assumed it would be different than glass. I WAS WRONG! It's amazing!

OK.... So far today I removed the shocks and manipulated the A-arm up and down without a load feeling for any grit or stiffness. NADA! Smooth as glass. I also put the wheels and shocks back on and checked the ball joints for smoothness the old fashioned way with a long steel bar under the tire lifting up. No play on the joint and no gritty feel or stiction. None of that grabby sensation you read about some people having.

With my dial indicator I checked runout on 4 different places on every hub..... The brake caliper hub, outer stud flange edge, outer stud flange end, and the outside edge of the studs while rotating the assembly. One stud was out .015 from the others. I re-torqued it (and maybe hit it with a hammer in the process) but it's within .005 now. All four wheel stud flanges were within .008 at the worst. I am surprised they would be that close. Additionally, I put the dial on the tire bead and spun the tire and it was absolutely perfect on all four tires. I couldn't measure it because the dial would hit bumps on the bead but visually on the pointer I couldn't see ANY movement. So the wheels and tires are spinning round and true at least on the sidewall and the only out of round seems to be in the middle of the tire. But at this point no one seems to have a "to much" out of round spec. Not my dealer...America's Tire... or even Nitto when I called them.

Tomorrow I'm going to spin up fronts and rear on the car and see if I get a vibration.....I'm running out of ideas.

I was the Tire and Wheel Manager for Ford Motor Passenger cars many years ago. One of our biggest issues was force variation because of sloppy production processes at the tire manufacturer. Michelin was the only manufacturer at that time that could meet our specification for maximum force variation. We found that coincidentally Michelin had the lowest warranty for tire balance on our new vehicles. The physics of the problem are related to overlapping splices in a tire that are either too thick or are aligned with other splices so that they are in the same sector of the tire. This causes a change in spring rate of the tire which causes a vibration under load. You can have 0 run out and perfect balance and have a tire that shakes like hell. A "bad set of tires" in NASCAR is sometime related to this problem although race tires are more closely controlled than street tires.
We offset bored our aluminum wheels a few thousandths and then matched those offsets using the valve stem hole and the manufactures mark for highest force area (yellow dot) to help cancel this variation. If a tire is truly bad the only fix is to replace it. All tires have force variation it is the magnitude that can get to you lighter cars are more susceptible than heavier cars. All this is just to suggest you might have a tire quality problem.

jhv48 · #3 (**permalink**) 08-01-2017, 05:11 PM

If there was no vibration/shimmy in your car until you swapped tires, then the new tires are the problem.
I would return to your retailer and have them fit a new pair.

wanab5150 · #4 (**permalink**) 08-01-2017, 07:16 PM

JHV48 maybe you have more swag than I do but so far they're not willing to cough up a set of new rubber without some visible or invisible defect which other than my word I can not prove other than the car vibrating.
Now if I'd had the foresight to take him for a ride before I bought the tires maybe I'd have a better chance. Then again, I've never in 55 years of driving had this issue.