vibration while braking ONLY

[justin hall]

Hi, the front end of my car is vibrating under braking. The amount of vibration increases the harder I brake. First guess was warped rotors, but that ended up not being the problem. Second guess was wheel(s) out of balance. Wrong again - assumed that was the case because problem is only under braking.

Any other ideas? The car is up at Niello Acrua and at this point they are scrathing their heads.....but at least they have given me a CL in the mean time.

------------------
Justin
'98 NSX-T Blk/Blk
· Comptech headers / exhaust / airbox
· Dali Racing / Brembo big brake kit
· Koni adjustable suspension w/Comptech springs and sway bars
· Volk TE-37 17/18” wheels
· Wings West side skirts and rear spats

 

[swede]

Wheel bearings? but my bet is on the discs.
Do you feel it in the "chassie" or in the steeringwheel?

 

[Edo]

Try removing the brake pads and sanding them against a flat surface.

 

[DutchBlackNsx]

I found the NSX very sensitive for any mis-adjustments on its wheels and tyre wear.
If it is not the discs, i would try a different set of rims(and tyres) first. The tyres (and wear) can put you in al sorts of directions, though you might think it has nothing to do with it.
I spend a couple of hundred dollars alligning the wheels because of an off-centre steeringwheel, and it turns out to be a slightly worn rear-tire (not visual).
Because the NSX is very sensitive, it could have to do with the rear brakes, but thats only a quick quess, since your problem is worse when braking hard.

Try the suggested brakepads well.

Have fun,


M.Plasmeijer
Holland
1993 Black/black

 

[Chris W]

Justin,
I agree with swede. If you feel the vibration in the steering wheel then my bet is on the rotors and/or wheel bearings.

Variation in the thickness of the rotor or uneven spots on either rotor face will cause the brake pedal to pulsate or shudder when the brakes are applied. Any unevenness in the rotor will be exaggerated while breaking and that vibration is transferred to the steering wheel. Check for discolored surfaces on your rotors or uneven pad wear. Discolored surfaces are indications of "hot spots" in the rotor which cause uneven friction points along the surface that the pads come in contact with. End result; VIBRATION (I would not advise sanding your pads) If they are worn unevenly then something else is causing the problem and all you're doing is prolonging the situation which could end up costing your hundreds of dollars to repair.

Let us know what you find out.

If the steering wheel gets the shakes at high speeds with no brakes applied, you may have unbalanced wheels or uneven tire wear.

 

[justin hall]

thanks for the inputs guys. first impressions were rotors, but Comptech said they were true. they turned them minimally just to be sure. with that said, the vibration is still there. the rotors are true!!

I had all the wheels balanced even though I know that was not the problem, did it just to be sure, and it had been a year.

I will try some of the other suggestions. Andie, thanks for the private.

Justin



[This message has been edited by justin hall (edited 05 May 2001).]

 

[hejo]

Hi Justin,

Hey I think DutchBlackNsx might be right. I too have found the NSx to be really sensitive on tire wear and even more on wheel alignment. I wouldn't discount this area too fast.

BTW I blew through my first set of tires, all 4, in under 5k miles. When I got my new tires I had my car alignment checked 3 times until it was perfect. Completely drove the NSX tech crazy

Now I have over 10k miles on them including my rears. I drive just as agressive if not more. This is probably the most sensitive area for the NSX.

------------------
Hal Jones
Lake Oswego, Oregon
95T Blk\Blk SportShift

 

[weiku]

I spend a couple of hundred dollars alligning the wheels because of an off-centre steeringwheel, and it turns out to be a slightly worn rear-tire (not visual).
**********

I call this type of apparent misalignment "thrust steer", because the car will want to "steer" to one side, even with the steering wheel straight...it is caused by a misaligned or otherwise non-kosher rear end. If you have, say 10mm too much toe in on the right rear, for example, and the rest of the corners are alignment properly, and your tires are in good condition, and everything else is the way it should be, the car will still steer to the left, even if the steering wheel is spot-on straight (centered).

 

[johndoh]

My rears are wearing down way too fast. I've only put about 1500miles and I'm down to less than 40% treadwear. At this rate, I've probably got about 2k miles(max) left until I'm down to the wear-bar. My first set lasted me 5500miles (I probably could've went 6k until I was down to the wear-bar. My driving habit hasn't changed from my first set of tires and I probably drive even less aggressively. Very odd...

Anybody know of a good place to do alignment in the Seattle area? Do dealerships do a good job with the alignment?

 

[DutchBlackNsx]

If you have, say 10mm too much toe in on the right rear, for example, and the rest of the corners are alignment properly, and your tires are in good condition, and everything else is the way it should be, the car will still steer to the left, even if the steering wheel is spot-on straight (centered).

*******************

Youre right, but i found the steering wheel -off-centre, but the car was going straight, allways, when braking hard, or accelerating hard the car was also going straight, though the steering wheel was off-centre.
The only thing i noticed, and thats one off the reasons i blamed it on tire-wear, was when i was braking hard, the steering wheel was going to the centre....(odd or what?)

On every aligment job i was next to the car, and also checking the alignments on the computer (with cords and lasers).

Have fun,

P.L.M. Plasmeijer
1993 Black/black

 

[FAQ Nazi]

Brake shudder:

http://www.nsxprime.com/FAQ/Troubleshooting/brake_vibration_fade.htm

Tire life:

http://www.nsxprime.com/FAQ/TireWheel/tiretech.htm