Wheel bearing problems on track??

[bharpensx]

NSX-Tech:

I developed a problem rather quickly at a recent track event at VIR and I need some solid technical input on this as it is a hard problem to diagnose, or so it seems. First of all, the car is in very good shape and had just passed two technical inspections before going to VIR this past Friday. I am throwing in some facts here also, which are likely irrelevant, but it can't hurt. My car is a 92 NSX with Basch Supercharger, Comptech 6 Speed and 4.55 R&P and Dali Racing Sways, currently the rear is on but the standard NSX is on front. It has been this way for a couple years. Drivng the car on street and highway for the last couple weeks has been event free. Everything about the car feeling especially good. So I went to VIR (South Track for those who know it. In the first run of the day about four laps in I detected kind of a rump-rump-rump sound when cornering at speed, equal to the rotation of the tires. I pitted and hypothesized, drove around the paddocks and the skidpad, not able to tell anything was wrong. I could feel this in the steering column as well as hear it.

I thought carefully about it and then thought, this only happens when cornering or going around a curve to the left and when the front right tire is fully loaded. In the second run of the day (I only ran one cautious lap-to test this), I went in with this hypothesis and it proved true. On this course there are two semi connected left curves, one on a downhill pitch...and it was during these turns that I proved it to myself, that there is a problem when cornering to the left. Also, because of the lie of this track, I also proved that it is not braking dependent.

So I took my NSX to the dealer today, informing them that they would not be able to reproduce this symptom, but asked them to check what might be the problem in the front right wheel. They could find nothing wrong. They said that the air dam might be flapping against the tire and seemed loose, but that didn't hold true to me when I also felt the rump-rump-rumping in the steering wheel. There only other alternative was the front right wheel bearing (and they were very reluctant to offer this, since they couldn't be sure anything was wrong with it and it is a $600+ replacement) as a solution. So now I offer it up to you NSX Track tech guys. Based on my description and your experience, what could it be? What might it be? And the tire and brake appear fine, and are doing fine in spirited city/highway driving.

Thanks,

Bill Harpe
Durham, NC

 

[Briank]

This is a long shot but worth a look:

http://www.nsxprime.com/forums/showthread.php?threadid=17817&highlight=axel+nut

 

[2slow2speed]

If it's a wheel bearing going out, you should be able to tell because it will start making a fairly noticeable sound, any reputable shop should be able to tell you right away if it's the bearing.

You did not mention what kind of tires/wheels you are running as well as the suspension and how low you have your car.

Are you sure that your tire is not rubbing inside the right fender under load? Have you examined that area for signs of scrubbing, etc?

Just wanted to throw some other ideas out given that the dealer could not pinpoint the problem.

Ken

 

[ncdogdoc]

I think Ken may be on track here. If you are running wider tires on stock wheels or wider wheels, or even spacers, there is the chance that a tire may be contacting the inner fender (aluminum) or the fender liner at the bottom edge just below the headlight, or lastly, the louvered portion just behind the AC condensor and fan setup. Any of these three areas should show some wear, albeit small if only noted for less than five laps total.

Try reproducing the action in a local shopping center parking lot with the same type of tight turns in the same direction. Then try to reproduce it with tight turns in the opposite direction. If Ken's hypothesis is correct, it may have just been noticeable during the loading in those particular corners (I am guessing the two lefts after the bitch and before fish hook).

You may have to try and find a parking lot with a noticeable drop in height to reproduce this both left and right.

Good luck.

 

[Andrie Hartanto]

Ken's theory is very plausible. However, I had similar situation on my civic. Only happened under load at the track. Couldn't replicate it otherwise. ended up to be bad wheel bearing.

 

[Larry Bastanza]

Edit,

Ken and Gary said it all!! I would suspect the wheel bearing or possibly a bad tire.

HTH,
LarryB

 

[bharpensx]

More information on troublesome NSX

Sorry for not giving all the information needed to help analyze this problem. The wheels and tires on the car were the 16-17 wheels from a later model NSX. Original correctly sized Yoko A022s on them. The car has not been modified to lower it in any way. When I first felt this sensation it was kind of like the whap whap whap you hear and feel when you have a flat tire, yet all tires were fully inflated (I checked before and after). I also kind of discount the idea of something rubbing against the tire as it was whap whap whapping consistently with tire rotation, if it was something rubbing the tire there is no reason to believe that it wouldn't have been making a noise constantly rather than rhythmically.

Bill Harpe.
Thanks for your help so far.

 

[DanO]

Did you check your lug nut torque all the way around? Could also be a stuck front caliper or pad. I think you are wise to try to get this figured out before attempting anymore hot laps. In my experience with this car, when something doesn’t seem (sound) right, it usually isn’t. I would not rule out the rear hub either.

Good luck and keep us informed.

DanO

 

[NSXT]

Sometimes these noises lie to you, and what feels/sounds like its the front is actually the rear and vice versa.

Check all 4 wheel bearings, being sure to remove the rotors to do it. Should it be a rear bearing, look at ViperDriver's thread discussing improperly made rear hubs. This is why ViperDriver experienced the 'loose axle nut' symptom.

 

[Larry Bastanza]

Interesting.

A while ago I was working on a totally different vehicle(this was a Ford Windstar) that had a bad bearing. When the machine shop pressed the hub out of the bearing, it looked identical to this. The press operator took a brief look and recommended a new hub. He thought it was quite common, he said, "some are OK and some are worn." I did not think about it any further, just went with his recommendation. BTW, the other side of the car was OK.

Food for thought, this is by no means limited to NSX parts.

LarryB

 

[Like007]

Nose

Hi
I had a same problem at the track
All what it was is a ruber from the track
stuck to my tires
Igor

 

[big al]

I have a similar problem with my 91' and it occurs at 60mph, 80mph, and 100mph in a straight line. The steering wheel shutters at these speeds in a straight line, not in turns. Is this a hub or bearing?

Thx
Al

 

[docjohn]

Nice searching!Your problem sounds like a front wheel/tire is out of ballance.

 

[nsxtasy]

I have a similar problem with my 91' and it occurs at 60mph, 80mph, and 100mph in a straight line. The steering wheel shutters at these speeds in a straight line, not in turns. Is this a hub or bearing?

Remember, when diagnosing a problem, start with the things that are most likely and easiest/cheapest to check.

The most common cause of vibration problems is wheels/tires that are out of balance, or other wheel/tire problems (e.g. wheel bent or otherwise out of round, defective tire, etc). These are very easy to check. If you have another set of wheels/tires known to be good, or if you know of another owner in your area with a spare set known to be good, just swap the wheels/tires onto your car and see if the vibration still occurs. If not, then you know it's something about the wheels/tires; if so, then look at the hubs, bearings, and other parts on the car itself.

 

[Andrew]

I had some really strong shuddering through the steering wheel under heavy braking; changed the front disks and pads, cv's and bearings...

Turned out that the rear pads were worn... Which was really annoying; because they started to squeak just as I was leaving for my fishing trip... 1600km later when I got back home >_<

'99 Accord Wagon not an NSX though, but things like this tend to be generic between cars

I'd say the first thing would be to get your wheels balanced and aligned...
Make sure everything is tight... maybe change the break pads and get the disks machined. Then fa iling that get a new bearing.