Hi everyone,
can somewhere please tell me causes about the shimmy-effect? What can I do? New bushings or other specific reasons?
Many thanks,
Anton
Other more experianced people will pipe up soon. Bushings are the problem sometimes. Also the pitmen arm ball as well. Jack up the front of the car and wiggle side to side and top to bottom, while looking at the linkages to find the location of the slop.
Check you toe in and caster.
Best way I have found to check toe-in is use a square or a piece of something that is square and measure out from center of contact point of tire to the ground and measure out the same front and back of both tires the same distance. Take your square and make a line to the ground from center of tire tread or the same side of the tread to the ground and make mark front and back of each tire. Then measure front and rear lengths. Front should measure 1/8 to 3/8" shorter that the rear dimension called toe-in.
Caster is measured with other means but you are supposed to have 3-5 degrees of positive caster. Meaning the lower bushing is forward of the top. I think around 1/4 to 3/8"
Other things that are common wobble makers is loose front wheel bearings.
Jack up front tires, spin tire and put chalk mark on tread of tire while spinning. Measure chalk mark to chalk mark. Front minus rear equals toe-in amount. When checking front end for slop, also check for a stuck spring as that can also contribute to it. Also follow the other advice in this thread.
Replacing the worn radius rod ball cap fixed it in my car.
Hi,
this is a great forum.
Many thanks to all for your suggestions.
With kind regards ... Anton
Rather than use the chalk line method, I screw a small screw into each tire, and then use that as a measuring point front and rear. It covers the possibility of an untrue wheel, and give you something to hang the tape measure on if you are doing it by your self. If you use the chalk line method, it is best to scribe a line in the middle of the chalk line to give a precise measurement.
Best
Gus
Tire pressure???
In my experience, it's almost always a number of things that taken together cause the problem. You really need to go through the whole front end (king pins,tie rod ends, pitman arm etc.), repair any issues and get the whole thing up to par. A little play here and a little play there can add up to a lot of shimmy. In any event, it's a safety issue first and foremost so you shouldn't just be going after just one cause unless you know that everything else is OK.
Check the spring perches for orientation. Some cars were fitted for Hassler shocks then had them removed. If the perches weren't switched side for side, then the caster will be wrong causing bad shimmy. I suppose an axle installed backwards would have the same effect.