Steering Wheel Vibration - Exhausted almost all avenues!

[mclarenf1kid]

So I'm 3 months into ownership of my NSX. New territory, but I've learned quite a bit from this message board and reading various write-ups.

As with any build I do, maintenance has come first.

In the past 3 months, I've installed Tein Flex Z coilovers, brand new ESR 18" wheels with Federal SS-595 tires, gone through suspension checking play and wear in the control arms, bushings, tie rods, etc. Brake rotors and pads are in excellent shape.

After an alignment, new wheels and tires mounted and balanced, physical brake tests for rotor surface issue and vibration, tests done for wheel bearing and tie rod........my steering wheel still vibrates at higher speed. And its intermittent. And its irking me because the car drives beautifully. The vibration really degrades the car. It does it every so often at lower speed. But once you get past 70mph, it's pretty consistent.

I'm at a loss. I read about these cars suffering with steering rack knock. I have no noise from the rack over bumps, and did the test to check for play; and nothing. Absolutely solid.

My last resort is to check if the brand new tires are out-of-round. This is the only thing I can think of.

Am I overlooking a possible NSX-exclusive issue that these cars suffer with when it comes to vibration?

Let me know your thoughts. Thanks!

 

[docjohn]

have the wheels road force balanced

 

[mclarenf1kid]

Definitely a good suggestion.

 

[ajmr2]

I'm at a loss. I read about these cars suffering with steering rack knock. I have no noise from the rack over bumps, and did the test to check for play; and nothing. Absolutely solid.

It's not clear to me how you tested for play. The tip off that it's the steering rack is if you're sitting still and turn the wheel left to right back and forth. You'll hear a clunk. Hopefully that's not it, cuz it's an expensive rebuild. As already suggested, spin balancing the tires on the car will reveal if they are round and/or out of balance.
Good luck!
AJ

 

[mclarenf1kid]

I'll double check that when I get home, but I'm 99% sure there's no noise.

I did check for play with the vehicle parked by turning the wheel. I also jacked up the car, turned the wheel at full lock and felt inside tie rod boot for play (watched a video that showed the procedure). No issues there.

I checked for play on both front wheels, shaking the wheels 12 to 6, and 9 to 3. No movement. Bearings spinning freely.

Thanks for the tip!

 

[MotorMouth93]

Check the steering column U-joints.

 

[goldNSX]

Did you do a brake test after fitting new tires? Then it's possible that the tires turned on the rim and are out of balance now. Don't ask me how I know.

The NSX with the manual steering rack is very sensitive to unbalanced tires. You get very much feedback in the steering wheel overall but at the same time you feel any unbalance too. You can't have one without the other. When my NSX sits for more than two days and going straight on the highway it feels like the tires are unbalanced for about 5 miles, after that it's much better. They need a new heat cycle to get round again. This can be felt in the NSX very clearly and I haven't had is so much pronouned in any other car I've ever driven.

If that if your case your only chance is to drive it some miles right before you balance the tires again.

 

[BBVNSX]

If you install an NSX-R or S steering wheel this feeling through the wheel will be even further increased! I Know this and I have EPS!

Did you do a brake test after fitting new tires? Then it's possible that the tires turned on the rim and are out of balance now. Don't ask me how I know.

The NSX with the manual steering rack is very sensitive to unbalanced tires. You get very much feedback in the steering wheel overall but at the same time you feel any unbalance too. You can't have one without the other. When my NSX sits for more than two days and going straight on the highway it feels like the tires are unbalanced for about 5 miles, after that it's much better. They need a new heat cycle to get round again. This can be felt in the NSX very clearly and I haven't had is so much pronouned in any other car I've ever driven.

If that if your case your only chance is to drive it some miles right before you balance the tires again.

 

[goldNSX]

If you install an NSX-R or S steering wheel this feeling through the wheel will be even further increased! I Know this and I have EPS!

I can imagine that. In my case it is disturbing even with the stock steering wheel.

 

[TomCat]

If its irregular and at different speeds, check that you don't have a broken tire cord/belt. The tire/wheel can be dynamically balanced but can get out of round at certain speeds due to internal (not visible) tire damage.

Jack up the wheel until it is just barely off the ground/garage floor...and spin the wheel/tire by hand to see if the distance/gap between the tire and floor remains constant. I chased an issue like this on a new set of tires for months before I found it by accident. Check both sides (and actually all four tires).

PS-road force balance finds the same issue

 

[emac]

Did it vibrate prior to installing the new wheels/tires? If not and you still have the other wheels/tires fit them and see how it does. Where in SC? I am in Greenwood. As others have stated force balancing is good. Not all tire installers and balancers are the same. Find someone that really knows their stuff. Years ago there was a place down in Aiken called Eubanks and they would balance the tire on the car and that worked great. They would also true the tire to make sure it was round. I think that was before force balancing came along.

 

[crxguy52]

What brand tires? I designed tires for a while, and they can do all sorts of weird things, even if they appear round. Based on how the belt joints were made, you could end up with a round tire but non-uniform radial stiffness which can cause vibrations, etc. Cheaper Asian import tires typically skip out on quality checks to save money, whereas the bigger name brand (and $$) tires won't.

As for the inconsistency, it may be some sort of non-uniformity in the two front tires going in and out of phase. If you go around a long sweeper, you'd be able to feel the vibration get better and worse as time goes on. As others have mentioned, a road force balance would help with this.

 

[TomCat]

Years ago there was a place down in Aiken called Eubanks and they would balance the tire on the car and that worked great. They would also true the tire to make sure it was round. I think that was before force balancing came along.

Small world-I used them when I lived in Edgefield/Trenton and worked at SRS.

 

[SMYLDOC]

Discount tire had to put 3 front left Yokohama Advan AD08R tires on my front left 92 NSX to find one that was not out of round. So don't just assume it's the less expensive tires that have this problem, it can happen with any make, any model.
Good luck

 

[Old Guy]

Discount tire had to put 3 front left Yokohama Advan AD08R tires on my front left 92 NSX to find one that was not out of round. So don't just assume it's the less expensive tires that have this problem, it can happen with any make, any model.
Good luck

Interesting point I discovered. Tire manufactures (some / all ?) road force test and sort their tires. The best tires get sent to the car manufacturers if the tire is specified as OEM fitment. The next best get supplied to the front line tire vendors and the rest get supplied to the heavy discounters. So, getting the same brand name and model tire from different vendors does not necessarily guarantee the same quality of tire.

With respect to the road force balancing, some tire manufacturers will mark the tire after testing with a dot indicating where the stiff point is in the sidewalls. This dot is to be lined up with a marking on the wheel indicating where the lowest spot is in terms of the rim eccentricity. This may not eliminate; but, helps to minimize the effect of wheel eccentricity and sidewall variability. Of course, this only works if the rim has the out of round markings. Tires also have different colored dots indicating the light spot which can be lined up with the valve stem mounting hole. This has become important with TPS monitoring systems which add weight at the valve stem. I don't know what takes precedence, matching up for eccentricity or matching for tire weight.

 

[Jinks]

^So that is what the little colored dots are on my tires. Never would have guessed.

 

[emac]

I have had luck rotating a tire on the rim 90 degrees and rebalancing, similar to the dots. As I recall the red dot is the heavy spot and goes opposite the valve stem. Some tires just suck and need to be on another car.

 

[JoseJA1979]

I'll double check that when I get home, but I'm 99% sure there's no noise.

I did check for play with the vehicle parked by turning the wheel. I also jacked up the car, turned the wheel at full lock and felt inside tie rod boot for play (watched a video that showed the procedure). No issues there.

I checked for play on both front wheels, shaking the wheels 12 to 6, and 9 to 3. No movement. Bearings spinning freely.

Thanks for the tip!

Have you tried putting your stock wheels back on and see if it's the ESM wheels that are the culprit?

 

[mclarenf1kid]

I purchased my car with a set of old Motegi DP5's installed on it, so unfortunately I didn't receive a set of stock wheels. However, the vehicle did have a faint tremor mostly due to VERY old tires; in which I didn't worry about diagnosing because I had ordered new wheels. But I could find another set up wheels to bolt up and see if that could be the culprit.

 

[TomCat]

Discount tire had to put 3 front left Yokohama Advan AD08R tires on my front left 92 NSX to find one that was not out of round.

I also have had issues with internet ordered Discount Tires (twice). That being said, they really have stepped up their game for customer complaints.

 

[goldNSX]

I also have had issues with internet ordered Discount Tires (twice). That being said, they really have stepped up their game for customer complaints.

A few decades ago the discounters got B-quality while the official distributors got A-quality regardless of what product. Not sure if that is still the case. It depends on if they can divide the quality into two segments during production. As the pricing of the official dealers have become 'competitive' enough I go and get my tires there instead of hunting after the small discount.

 

[TomCat]

A few decades ago the discounters got B-quality while the official distributors got A-quality regardless of what product. Not sure if that is still the case. It depends on if they can divide the quality into two segments during production. As the pricing of the official dealers have become 'competitive' enough I go and get my tires there instead of hunting after the small discount.

Not to change the subject but I live in rural North Carolina (...think Andy Griffith's Mayberry) and I tend to need odd sized tires so I have very specific sizes delivered to my door and use my wife's SUV on the weekend to get them (and the wheels) to my favorite shop to mount.

 

[Valhalla]

You have not mentioned whether or not you are using concentric spacers and if your lug nuts are stock or after market. That could make a huge difference too but I would start with road force balancing. Depending upon the shop you could get life time balancing and that is worth the cost right there. Concentric spacers are cheap and available thru SOS.

 

[docjohn]

very true the lugnuts need to have the right shape for the wheel seats....and not having the hubcentric rings, for me has meant I sometimes have to remount the wheels to get rid of bad vibrations...que the beach boys...

 

[davidf]

very true the lugnuts need to have the right shape for the wheel seats....and not having the hubcentric rings, for me has meant I sometimes have to remount the wheels to get rid of bad vibrations...que the beach boys...

I know its a late post but i had this issue for quite some time. Turns out stock lugnuts do not work with aftermarket wheels.