45 MPH shimmy

[adam412]

My '74 412 wagon shimmies (the steering wheel vibrates pretty strongly) when I go up or down past 45 MPH. When i took off the steering wheel and signal/washer assemblies, in the little well at the top of the rest of the column there were bits of a plastic ring that had disintegrated. I have been trying for several months to find the part number and availability of the part. The folks at Bughaus had two suggestions, either part # #111-601B or part #111-535D.

Someone else I spoke to said that replacing this ring would correct my shimmy problems, and I hope they are correct, as I am new to getting under my VW and would like to avoid replacing the steering dampener.

Any suggestions? Anyone know the correct part # and where I could get it?

Thanks in advance,

adam.

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Il y a des fleurs partout pour eux qui veulent bien les voirs. - Henri Matisse

[ray greenwood]

If the shimmy starts at one point and ends...its not the damper. The damper mainly helps on bump steering and absorbs stray vibrations. This sounds more like a balance problem, or an alignment problem. If the wheels are in balance, jack up the car, sit in front of the wheel and spin it. Chances are you will see what appears to be a difference in width on the sides of the rim. If you have stock wheels, these are flat or spread spots that are caused by sitting still for years. Most sets of wheels have at least one. The most likely cause of your shimmy is an alignment problem with the toe in. It can be caused by too much toe in...or...(and this is most probable) worn control arm and radius arm bushings. Toe in is there, because forward motion on the wheels tend to spread the wheels outward from the force. So they start toed in...so at road speed, they are straight forward. If your bushings are worn, or the toe in is too much, instead of getting a gradual spread with increased speed...on both wheels....you get one flexing farther than the other...faster. This effectively causes one wheel to make a slight steering change one way....pulling the tie-rods with it...and the other quickly counteracting it...in effect...a shimmy. There is nothing in your steering column which will affect it. The plastic ring inside the column is most likely part of either the turn signal assembly or the wiper/washer assembly. There are no guide parts in the column except for the ribbed steel bushing that slips in behind the circlip. A little hint. Replacing parts on the 411/412 piecemeal or as they wear out, will cost you a bundle in worn parts. I have learned the hard way. The suspension members are very long on this car...and generate lots of leverage. One new or old part will destroy everything attached to it. If you replace ball joints....replace both of them AND the tie rod ends...including and especially the centerlink. If you have never replaced the centerlink yourself...I guarantee it needs it. They are still available...prices ranging from $79-$141...go figure. TRW part # DS-858. If you drill some grease holes in the ends...and keep it greased...it will last forever. If you replace bushings...replace them all. Rabbit control arm bushing press in and work well. They are about 1/16" too short on each end. Put a thick washer on each end. They are cheap also. The radius arm bushings can usually be reused...if not, any good rubber sales house can cut them from 1/2" thick urethane sheet for a few bucks (use 70 durometer). The centering rings that go underneath them...are the cause of most shimmies in most 411/412. Not available...but I usually make them from Delrin rod stock on a dremel router. Its just a grommet missing one flange...but you gotta have it. I recommend getting a box, collecting the parts and doing everything at once. I replaced 2 sets of ball joints before I realized my centerlink and iffy struts were destroying them. Ray