dms
11-07-2008, 02:31 PM
I had the pleasure of spending a week with 3 of the top Pedders dealers in Australia, as well as 5 core people in the main office. Before the beers became overpowering (yes, the Aussie love our beer and hamburgers!) we talked extensively about product issues in Au. I am not bashful about my suspension knowledge, but I will tell you they make me feel like a suspension beginner! They have nearly 2 years more experience than us on the ZETA platform, plus collectively, have done a lot more installs than us, plus have dealt with a lot more problem cars than us. Here are 2 areas that they have found that may resolve drifting and pulling issues:
A. On the GTO forums, several years ago, I started a thread that discussed dynamic alignment issues. Turns out there are some dynamic alignment issues. What Pedders has found on a lot of is a dynamic problem with the rear. Due to an accumulative amount of non compliance with their bushes, they have found the thrust angles, which is the relationship between the the front and rear tires, can become excessive, thus causing drifts/pulls. How do they know? By process of elimination and this is how:
1. Accurate 4 wheel alignment
2. swapping tires
3. making major changes in caster bias with no difference
4. swapping out the bushes in the rear, problem fixed.
Now there have been a number of drift/pull situations on the G8 out there, but the problem is not bad enough to call it a pattern failure. But Pedders Au has fixed a couple of dozen of these problems by upgrading rear bushes. GM racing, found there were issues with the back end, especially toe changes, until they upgraded the rear bushings on the Racing Camaro that they are doing.
Why is this just on some vehicle, limited fortunately, and not on all? We can only speculate that it is possibly related to cradle and body tolerances. When tolerances get close to a max level, these things can occur.
So this is something for all of you to think about.
B. Also, it is blatantly obvious that GM is having a bolt problem. How do I know? Because comparing OEM installs of the components at the factory from the first 888 vehicles, which I have done 2 of them, to say the last one that was the 15,000 or so, they are lockiting nearly everything. What has Pedders Au found? The upper inner forward rear control arm pivot is getting loose, and causing noises, but also causing changes to cambers. This is one of those parts that you really cannot see well without dissassembly. Pedders will soon come out with a permanent repair for this. The Beta testing parts have been done. Now it is a matter of production, and distribution.
So just a heads up on this. I will be making major posts very soon on this topic
thanks
mike
dms
A. On the GTO forums, several years ago, I started a thread that discussed dynamic alignment issues. Turns out there are some dynamic alignment issues. What Pedders has found on a lot of is a dynamic problem with the rear. Due to an accumulative amount of non compliance with their bushes, they have found the thrust angles, which is the relationship between the the front and rear tires, can become excessive, thus causing drifts/pulls. How do they know? By process of elimination and this is how:
1. Accurate 4 wheel alignment
2. swapping tires
3. making major changes in caster bias with no difference
4. swapping out the bushes in the rear, problem fixed.
Now there have been a number of drift/pull situations on the G8 out there, but the problem is not bad enough to call it a pattern failure. But Pedders Au has fixed a couple of dozen of these problems by upgrading rear bushes. GM racing, found there were issues with the back end, especially toe changes, until they upgraded the rear bushings on the Racing Camaro that they are doing.
Why is this just on some vehicle, limited fortunately, and not on all? We can only speculate that it is possibly related to cradle and body tolerances. When tolerances get close to a max level, these things can occur.
So this is something for all of you to think about.
B. Also, it is blatantly obvious that GM is having a bolt problem. How do I know? Because comparing OEM installs of the components at the factory from the first 888 vehicles, which I have done 2 of them, to say the last one that was the 15,000 or so, they are lockiting nearly everything. What has Pedders Au found? The upper inner forward rear control arm pivot is getting loose, and causing noises, but also causing changes to cambers. This is one of those parts that you really cannot see well without dissassembly. Pedders will soon come out with a permanent repair for this. The Beta testing parts have been done. Now it is a matter of production, and distribution.
So just a heads up on this. I will be making major posts very soon on this topic
thanks
mike
dms