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Jim Grant's Tech Tips
'88 Toyota Corolla, Bent Something
Q:
About a year ago, my Toyota Corolla ‘88 skid and ran into a side
walk (it hit hard, right hand passenger side). I felt it start shaking
while driving, I took it to a mechanic, he checked the front wheel (the
side it hit) and said, the rim was bent. I put on a new rim and the car
kept on doing the same thing. I took the car to a different mechanic and
he said "tires are bad" I end up changing all 4 tires. The car
is not shaking as much. I tried a different mechanic, he told me once
it hit the curb, the lower part of the front shock turned bad and he changed
it ($$$). It still shakes (when driving very slow 5mph, or about at 55mph
+ ). I went to a different mechanic and he said the other side CV axle
needs to be replaced, I am tired of spending money needlessly. Could you
please suggest something about that. I would really appreciate it......Nick
A:
There’s
no question that you bent something. Because the shake is related to the
movement of the vehicle, tire rotation, this tells you that the bent part
has to be turning. Identifying the cause is as easy as taking measurements
of the parts that turn. Any shop worth it’s wrenches will have a
tool called a dial indicator. A dial indicator measures in thousands of
an inch. That may seem extreme, but it only it takes the equivalent of
3 to 4 human hairs of variation in the wrong place to cause a shake in
nearly any vehicle. The test performed with a dial indicator is called
run out. A run out test proves if a rotating part is turning in a true
circle or is wabbling. Begin testing for excessive runout where the wheel/rim
bolts to the vehicle. That area is pretty tender to side impacts. Also
the axle is not out of question, but it should not be replaced unless
the dial indicator says it’s wabbling. An hour or so of good diagnostic
time should find the real cause.
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