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I'm surprized that no one seems to know what the Z-bar is for. It is not a sway bar or overload spring. It is meant to act as a camber compensator although it only works part time with the inherent slack in its stock installation. It is meant to prevent jacking, a phenomenon in all swingaxle cars, not just vw's. It is supposed to keep both rear wheels from going to the same camber extreme at the same time. Jacking is an effect that usually happens on bumpy roads in hard cornering. It is a combination of bump steer, a sudden rise in the center of gravity of the car and the fact that the contact patches of the rear wheels are moving closer and further apart from each other as they move up and down. Imagine a swingaxle car is in a hard right turn. The left axle is loaded down due to weight transfer and has the wheel in negative camber. The right axle has less of a load and is in postive camber. Now imagine the right tire hits a large bump, followed by a dip. The car rolls to the left. If the right tire loses traction during the flat-bump-dip transition inertia will send it towards the left tire and with the suspension all the way down at maximum positive camber. As the car tries to right itself by rolling back to the right the left suspension unloads and the left tire also goes to a positive camber position. Now both tire contact patches are closer together reducing rear track and stability, the center of gravity of the car is higher as body of the car is further from the tires reducing stability and increasing roll and the car tries to right itself by rocking back and forth. If it rocks back and forth violently the tires will have a hard time gaining traction and the susspension will keep jacking the car up. Now imagine the driver in this situation panics and locks up the brakes in a car with a high center of gravity, extreme positive camber, a small rear track, and lack of tracion at the rear wheels of a car with a high rear weight bias. The car is likely to spin out, roll over or go out of control. I use this example as it happened to me driving too fast throught the Santa Cruz mountains. It was very scary feeling the car roll to the left and right as it bounced back and forth in the rear. Luckily I had been taught to hit the accelerator and concentrate on aiming the front wheels in such a situation. Had I hit the brakes I probably would have spun out in highway traffic or gone off a cliff. It is a rare but fatal situation that was getting some attention by the late 60's. I think that it's especially dangerous because the cars can handle so well until, all of a sudden... Sorry this is so long. It's hard to explain. I hope it makes sense. Josh Brooks ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ List info at http://www.vwtype3.org/list | mailto:gregm@vwtype3.org ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~ Shameless link for search engines: http://listarchive.type3.org ~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~