Steering wheel slightly shakes left-right directions

ALZACK41

MEMBER
2000 TOYOTA AVALON
3.0L
6 CYL
FWD
AUTOMATIC
140,000 MILES

All this happened during the last month.
1) Both outer tie rod ends replaced and a four wheel alignment performed. Alignment was good, the car did not pool to any side.

2) But when driving, I noticed steering wheel slightly shaking up and down. Mechanic's advice was to replace both front struts, which was done with two strut-and-spring assemblies.
That replacement eliminated up-and-down shaking,
but new shaking in sideways left-right directions was noticed on the steering wheel.

3) This is what was done further on at the front:
a) both lower ball joints replaced.
b) both lower control arms replaced.
c) both sway bar links replaced.
d) Four wheel alignment performed again in the same tire shop.
Alignment was not so good this time. The left-right direction steering wheel shaking still was there,
and the car slightly pooled to the right when driving.
I pointed that to the alignment mechanic. His answer was that front wheel balance will make both symptoms go away.

4) Sour tire balance performed at SAM's Club.
Both front tires received static and dynamic balances.

5) This thorough tire balance decreased a little the above shaking, but the car still slightly pools to the right.

6) OK. Another alignment would eliminate car pooling to the right (That is what I thing).
But what about that steering wheel shaking right>left>right>left?
How can be that eliminated?

1 Reply

CARADIODOC

MECHANIC
33,916 POSTS

The steering wheel is round and rotates. Your description of shaking up and down and left and right confuses me. A tire balance problem could make anything bounce up and down, including the steering column, but that is quite different than a rotating oscillation. That type of vibration can be caused by one type of warped brake rotor, but it is more commonly caused by a broken tire belt. The clue is a balance problem will only show up at higher speeds, typically over forty five to fifty mph. A belt problem is usually easy to see at low speeds, like when driving through a parking lot. You will see the steering wheel turning left and right a little, once per tire revolution, and you may feel one corner of the car lifting up and down a little.

A broken belt will also cause a pull to one side. You can get an additional clue on front-wheel-drive cars by observing the car pulls to one side when accelerating, and to the other side when braking fairly hard. Worn control arm bushings will cause that too, but that should show up as the "before" numbers on the alignment printout are different than the "after" numbers from the previous alignment. In other words, something changed between the start of this alignment and the conclusion of the previous alignment. The symptoms from a worn bushing will change too during the drive cycle. To verify a pull is caused by a tire, switch the two front ones side-to-side, then see if the pull is gone or goes the other way.

If you can post the numbers for "camber" and "toe" for all four wheels, I can interpret them for you. Be aware all alignment computers can read camber to.01 degree accuracy which is a huge improvement over the 1/16 degree we could read to years ago before computers. The problem is all alignment computers can be set to display numbers to just the tenth of a degree. Some mechanics set them that way to make the alignments go faster, but today's cars need to be set more precisely. Many of the cars I aligned needed to have camber set.06 degrees higher on the left to make up for "road crown". You cannot do that when the computer is rounding off numbers and losing the accuracy. , 06 degrees would be rounded off to.1 degree, but.1 degree is too much for those cars. .04 degrees is okay too, but if it's rounded off, it shows up as 0.0 degrees, and that is not enough. If your mechanic has his computer set to read to just the tenth of a degree, you are not really sure what you have.

Remember too that a steering wheel oscillation, and a vibration, are caused by something that is rotating. Ball joints, tie rod ends, and struts do not rotate, so if they are worn, they can cause clunks and squeaks, but not vibrations. New shock absorbers and struts can dampen vibrations better than the old parts, but whatever is causing those vibrations is still there. If toe is badly misadjusted, the two tires will steer toward or away from each other. Once the sidewalls cannot bend and stretch any further, the tread will slide back, then start to walk away again, over and over. That can be felt in the steering wheel, and while that is an adjustment issue or a worn part issue, the tire still has to be rotating for that to be felt.