I don’t listen to their radio show because it annoys me how much they laugh at their own tired jokes. But today I read their column in the Statesman. The first topic they answered well, the second, not too well at all. It concerned someone who drove a ’98 Toyota Corolla on bad roads and experienced steering wheel shimmy at 60-70 mph despite having had the car’s wheels “balanced and aligned.” Click and Clack offered two possible explanations:
1. Tread separation on a front tire.
2. A loose tie rod end or ball joint in the front suspension.
Tread separation would have been caught by a proper wheel balance job. A loose tie rod end or ball joint has the following symptoms: Clunking and knocking at low speeds when turning or going over bumps. If a tie rod end or ball joint is catastrophically loose, a wicked “death wobble” vibration will be triggered when you go over a bump at about 30 mph or less. This vibration is such that you will pull over to the side of the road wishing you had a change of underwear with you.. High speed shimmy is not generally a symptom of a loose tie rod end or ball joint.
The following are common explanations for high speed steering wheel shimmy:
1. A wheel balance operation was not successful due to poor equipment, poorly maintained equipment or operator error — happens all the time. My 3/4 ton crew cab diesel truck has wheels too big to fit our shop’s balancer. NTB flat out cannot balance my truck’s wheels — after they tried several times I got disgusted and tore off all the weights they had put on and it shimmied far less! Recently, Discount Tire was finally successful on about the sixth try. This was with new Michelins and me standing over them telling them how to do it and insisting they use different equipment than what they had tried without success on two sets of new tires. And, that said, Discount Tire is one of the best of the “big box” tire chains.
2. Front tire out of round or rim grossly bent so the wheel/tire assembly is technically balanced but does not roll true.
3. Shimmies when brakes are applied at highway speed because of brake rotors that are not flat and of uniform thickness due to warpage from the repeated heat generated by braking. Probably 50% of vehicles on the highway have this syndrome to a greater or lesser degree.
4. Inner CV (constant velocity) joints on the front wheel drive axles can cause a wicked vibration up the steering wheel any time the gas pedal is applied at high speed and they are under torque. This is, in fact, particularly common with the drive axles used on certain Toyota Corollas and Geo Prisms.
All four of the above are commonplace, but Click and Clack only mentioned #2, (sort of).
If you think they are entertaining, that is a matter of personal taste. If you think their information is to be trusted, I regret to inform you it is not.
