Serious Steering/Suspension Problem...

[cobalt]

Okie...where to start...

Under moderate to hard braking, the car moves to the right. Now, notice I said "moves to the right" and not "PULLS to the right".

Here is what I mean, in detail. When the car is cruising along a flat, straight stretch of road, everything is fine: the steering tracks straight and the car stays on course. When I apply the brakes to a moderate of high level of brake pedal pressure, the entire car moves to the right, even while the steering wheel stays straight. Further, there is absolutely no pull of tug on the steering wheel. In otherwords, I let go of the steering wheel, apply the brakes, the while the steering wheel will stay straight...the car will move to the right. I actually almost feels like the front left (driver side) is moving "first"...and takes the rest of the front end of the car along for the ride...rather than a pull to the right which begins with the right front (passenger side).

Now, I know it's not the brakes...took apart the brake system, cleaned and reassembled it, etc. - brakes I know about, and mine are working fine. Also, there is no tug in the steering wheel when I apply the brakes...the car just gradually shifts to the right under moderate to hard braking.

Now onto suspension...looked it over on a lift, and everything looked in place...nothing loose, but will take another look at it this weekend.

I'll have the alignment checked this weekend as well...

But, this is a curious problem, because while the car moves under braking, there is no input feel in the steering wheel...any ideas?

TIA... -Andie

[This message has been edited by HomeDepotNSX (edited 26 March 2002).]

 

[1BADNSX]

If it isn't in the brakes, it is probably one of the components (bushings, tie-rods ...) that control toe. The cause might be from the rearend. Does it pull under hard acceleration? If so, the rear is more likely.

Bob

 

[cobalt]

Bob,

Thanks for the input here...

I was thinking about it some more...and I think it's probably in the rear...not really under hard acceleration...but I think it may be when I get on the brakes, as the balance of the car shifts, unweighting the rear end causes a toe change in the rear...resulting in thrust steer.

I'll put it on the rack this weekend and check everything out...

Thanks again, Bob... -Andie

 

[Edo]

Andie, sometimes when your tires have a belt inside break prematurely it may cause the same problem.

My Cobra's tires had a belt break inside the tire itself and the car would move to the left side every time you applied any weight to the front (IE braking) Normal straightline performance was not affected as the belt wear didn't show unless you loaded that tire more than normal.

Or it could be that one of the rubber bushings in your car has failed...
The Compliance Pivot's have rubber bushings in them and might cause the alignment to change under hard braking if oine of them was bad...

 

[nsxtasy]

Originally posted by Edo:
Andie, sometimes when your tires have a belt inside break prematurely it may cause the same problem.

My Cobra's tires had a belt break inside the tire itself and the car would move to the left side every time you applied any weight to the front (IE braking) Normal straightline performance was not affected as the belt wear didn't show unless you loaded that tire more than normal.

Edo,

How the heck did you figure out that the belt inside the tire had broken? That sounds like something that would drive you crazy trying to figure out...

[This message has been edited by nsxtasy (edited 26 March 2002).]

 

[Edo]

About 6 months of driving around swearing at my car.

I went crazy and dismantled everything from the steering rack to the suspension in the front end. Even had the tires dismounted.
I had a tire expert go over each tire inch by inch with his hand and some sort of pressure gauge device.

Sure enough, one of the front tires had a weak section (Where the belt actually broke) and the rest of the belt around the tire was just a little bit "Squishier" than the rest.
VERY hard to quantify, or find for that matter. But that was the ONLY thing we could find that was even slightly weird on a car with only 10K miles.

So, I changed the Tires, and voila..no more pull. In hindsight, I think maybe the tire should have been the first thing to check...but nope...I did like 9 million alignments, bushing replacements, bearing replacements, Hub replacements, engine mount replacements, Catalytic converter replacements (Hey thats what the Ford dealer said it might be...dont ask ME!!)
And a bunch of other crap.

 

[cobalt]

Thanks Eddie...

I'm gonna cross my fingers and hope it's just an alignment problem...perhaps one of the adjustments wasn't tightened down properly and has come loose. I hope it is not a bushing or compliance bushing...or even a tire. The S-03's I have only have 3k miles on them...so that would be a real waste if one of the tires (in this case, prolly the front right) busted a belt...

Stay tuned. -Andie

 

[Larry Bastanza]

Hey Andie,

How are you? We haven't talked in a while. Based on Edo's experience, would it be pretty easy to just do a 4 wheel swap with a Florida buddy? I guess it would take about a hour to rule out or in that possiblity.

HTH,
LarryB

 

[ACR_Motorsports]

If the problem is actually with the tires, and you only have 3000 miles on them, it should qualify for Bridgestone's Platinum Pact Warranty.

Originally posted by HomeDepotNSX:
Thanks Eddie...

I'm gonna cross my fingers and hope it's just an alignment problem...perhaps one of the adjustments wasn't tightened down properly and has come loose. I hope it is not a bushing or compliance bushing...or even a tire. The S-03's I have only have 3k miles on them...so that would be a real waste if one of the tires (in this case, prolly the front right) busted a belt...

Stay tuned. -Andie

 

[cobalt]

Update here guys...consulted with MB on this one in terms of potential alignment and/or suspension part problems...but since it felt like thrust steer (MB has a slightly different term for this), went and took apart the brakes in the rear...

Here is what I found...left rear caliper e-brake adjusted really tight...no idea how this happened, since I didn't touch it myself. The piston this caliper also took FOREVER to retract...kinda sticky.

I decided to run an experiment, and disconnected the e-brakes on both sides...braking was smoother, but ABS was freaking out. No ABS light.

(INSERT) Previous to this (yesterday - before taking anything apart), the car would throw itself into a wicked spin (rear end consistently sliding out to right side) when I slammed on the brakes. (END OF INSERT)

I tested the brakes on moderate to heavy braking...still moves to the right like before...but braking "feel" still more stable.

Well, I decided to upgrade my rear brakes in any case, instead of just rebuliding the rear calipers, which is where the problem probably is... So, since the rear calipers are toast in my book (nice shelf momentos)...I took the car into an industrial park around my work and gave the brakes an abusive workout...figured on a seized caliper/piston and a stuck ABS solenoid (which is odd, since I "exercise" the ABS often.

After flat spotting the front tires a couple times...ABS begins to work normally (stuck solenoid?)...no rear end snapping out under ABS-inducing braking...and further such violent braking manouevers did not flat spot the tires.

Also...the flat spotting wasn't bad enough that I can feel it while driving...just enough to put up a couple puffs of smoke.

-Andie