I would like to know if anyone has experienced any problem with their front lower control arm bushings.

 

Everyones input is welcomed also. I only ask because there are more and more cases arising about the front lower control arm bushings toward the firewall side are pushing out.


[Modified by Van Steel, 3:02 PM 5/23/2003]

 

I am ready to replace my second set of lower control arms due to bushing failure (02 Z06 6 K mi.). I know of number of Z06 autoxers and this is a chronic C5 problem with race rubber and aggressive (autoxing) driving. The alignment changes continually as the bushings move (less caster, increased toe in).

 

I align 5 - 10 C5s each week, mostly road racer types and haven't seen any bushing failure yet. Not saying it won't happen, I just haven't seen any.

Mark

 

If you use these cars on the track, it will happen. Just a matter of time. The front lower bushing "extrudes" out mainly due to braking forces. I have seen it on 4 different cars. The only service that can be done is to replace the entire arm (no Chevy service part for the bushing) or use aftermarket bushings (VBP, Global West, etc). I will try to get a pic today of out T1 car and you can see what it looks like after 8 races. We have to comply with SCCA rules so only Chevy parts for us (T1 control arms that have stiffer bushings). It gets so bad that the "a" arm will be hitting the aluminum sub frame metal to metal.

 

Sucks to be you, new A-arms :(

Hey what do you do with your old ones.
We set up some "pro-touring" muscle cars, maybe I could adapt them to that application.

I guess that because most of my customers are just getting into track events, they just don't have enough hours on course to kill their bushings yet. Seeing that none of them are going to run T-1, which replacement bushings do you like? As I can see that this will become an issue before summer is over.

 

Actually it is not only the lower front bushings that go away, it is the uppers as well. It is due to the brake torque. The lowers try to move to the rear, the uppers go forward. see lower front:

see upper:


We have used VBP urethane bushing kit on another car (2000 FRC) and although it takes a good deal of hand fitting and is a very royal PITA to install properly, the work well. The problem with delrin bushings is that they will not allow misaglinment, and they way that the aglinment cams work (rear especially) flex is necessary. The best would be spherical bearings, but it would be very noisy for street use and none of the above are allowed in T1 anyway.
You want the old ones? TBD, let me think about it...
BTW, I totally (but respectivly) disagree with the toe-out in the rear, even though you are correct about the dynamic bushing flex and the fact the rear is "rear steer". Please consider the dynamic case of acceleration. The wheels want to go forward, increasing toe out. Cornering forces want them to go toe in. When you are accelerating out of a corner and the weight is on the rear outside tire, you want to have it pointed towards the inside of the corner so that you can put the power down better. Eric Curran (very good Speedvision driver) suggested 1/4 inch (total) in on the rear. I did not believe him at first, so we spent an entire test day doing just rear toe testing. Toe out is downright dangerous on a fast bumpy track like NHIS. We found that Eric was correct, we run 1/4 inch toe in now. With stiffer bushings, we would probably go closer to zero.
:D


[Modified by ghoffman, 11:10 AM 5/25/2003]

 

very common issue with autocrossers

in SCCA stock, no choice but to buy new factory parts

a real PITA

 

quote
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I am ready to replace my second set of lower control arms due to bushing failure (02 Z06 6 K mi.). I know of number of Z06 autoxers and this is a chronic C5 problem with race rubber and aggressive (autoxing) driving. The alignment changes continually as the bushings move (less caster, increased toe in).
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We have dicovered this as becoming a more common prob. especially w/autoxers. We are working on a solution.

 

Can somebody post a pic of the stock (ie, not damaged) bushings so I can see the difference? My suspension's making some racket (and I autocross) and I want to make sure this isn't the cause....

:cheers:

 

:withstupid:

 

I saw that exact thing at Pocono this weekend on my friends car. I would put poly bushings in if not running a stock class.


[Modified by John Shiels, 10:13 PM 5/27/2003]