Russ Keller, a reader and good friend of 1967beetle.com sent the following information with photos to back up his studied position. His thesis called for “loading” the Z-Bar by altering the travel space at the bottom end of each Operating Rod. With the space filled, the Rods are “loaded”. They are not “waiting” for a “loading moment” when the Z-Bar will be activated.
Russ Keller says:
Because the Z-Bar was active only in harder turning as an anti-sway, it was too little too late.
On our ’67, we engaged the Z-Bar all of the time by installing a polyurethane bushing to take up the 2 inch slack prior to engagement. In this way it was always ready in play and we didn’t have the delay in rear suspension stiffness when needed. It was there right away and really improved the cornering and over-steer. Here are a few pictures we took when we installed the z-bar bushings. It was a cheap and easy improvement and the urethane came in black so it matched the look. It was a big improvement for little $$.
After a few hard test drives we experimented with the length of the test bushing.
Because we bought an extra long piece of the hollow material from McMaster-Carr, we could cut test samples. These ranged from 3 1/2″ down to 2″.
The 2″ was the pick by the drivers–my son, “VW Gary” (Gary Drennen from Gary’s Aircooled Service) and me. As I remember, since the 2″ bushing did not quite fill the space on the Operating Rod, that little bit of “slop” prevented the back (of the car) from feeling springy or bouncy. Springy is a technical term of art…..”Federnd” in the original German.”