Steering wheel not centered when the vehicle is on a flat road going straight

if it was correct pre alignment, then they should have corrected it.

 

You should check your tires, if the tires are not good then the alignment will (seem) to be off

 

Take it back, they can adjust the tie rod ends to center the steering wheel.

 

They should have test road after alignment

 

Centering of the steering wheel is part of the alignment job. So if it bugs you, ask for the work to be re-done.

 

Its a simple job to center since its already aligned

 

I test drove three Prius cs during my evaluation of the car, for my prospective purchase.

Two had steering wheels which were slightly to the left when traveling straight, on level ground.

One had a steering wheel which was spot-on centered, and which reverted to such centered behavior when the wheel was momentarily released.

I accepted the one which "steered straight", and rejected the two which did not "steer straight".

I suspect others have had similar experiences.

 

You must've had a patient salesman

 

Yes, and I was the only customer, too.

 

Here's insight.

You can correct an "off" steering wheel two ways:

1. Adjust tie-rod ends until it's correct.
2. Remount steering wheel on the spindle.

The spindle is a rod with many teeth on it, and it mates with the steering wheel. The teeth ensures the wheel can't spin on the rod no matter how hard you pull. Severe misalignment can be easily corrected here (been there, done it), but it won't have any adjustment for misalignment found by bumping the wheel one tooth over. If your misalignment is that minor, the only option is to adjust on the tie rod ends.

IF your steering wheel was level BEFORE an alignment, the mechanic didn't get the tie rod ends right. Making sure the steering wheel is level should be the first step in performing a front-end alignment.

I'm not sure why remounting the steering wheel should ever be necessary unless someone botched it early on.

 

The proper term is "splined".

The shaft end has a spline machined in it, and the wheel has a matching spline, one with an almost "interference fit".

The external spline, the one on the shaft, is usually obtained by "milling" it. The internal spline, the one on the wheel, is usually obtained by "broaching" it.

Either could be accomplished using a "shaper", a machine tool which operates on a push-pull principle, and which can machine external and internal splines, when using the appropriate application tooling.

Shaping is faster than broaching, and is well-suited to production work.

A competent alignment job would be to center the wheel and then to adjust the tie rod ends to be centered, and only then would the alignment to specifications be performed. This would give the customer an alignment which was correct, with a little leeway left and right for possible future alignments.

Should this not be possible, then the wheel should be pulled and the entire process be repeated until it is correct.

The interference fit between the wheel and the shaft is usually so tight that simply pulling the wheel is no longer a "simple" operation.

Besides which, the airbag system is in the way.

 

You would think that since its not physically connected to the steering linkage that it could be adjusted via the computer.

 

I'm pretty sure the Prius steering is an electric assist rack and pinion mechanical assembly, not steer by wire as you imply.

 

My Prius is about 98% straight after the alignment. The service rep also told me that they come that way from the factory. I would not bother fixing it if its not pulling to either direction.

 

Just read through all the responses. And it occurred to me that nobody defined what "adjusting the tie rod ends" did; and, if you didn't know, that might be slightly confusing.

So, behind each front wheel there's a knuckle where the wheel, the shock absorber, and some heavy pieces of metal come together. It's all rigged so that the wheel can swivel back and forth. On the back (as in, towards the rear of the car) a long rod is attached to the knuckle; the other end of the rod is attached to rack and pinion steering assembly.

The rod is attached with a ball and socket to the knuckle; as you turn the steering wheel back and forth, the rack in the rack-and-pinion goes back and forth, too, and pulls/pushes the two rods (one to each wheel) so the car steers.

The tricky bit: the ends of the rods are threaded. Loosen a lock nut, turn both rods (they rotate along the long axis) in the same direction and the front wheels either splay out (toe-out) or turn in (toe-in). Getting that correct is quite a bit of the fun in a front-end alignment.

However, once that has been done, suppose you turn the rods by, say, 1/2 turn in opposite directions? Well, one rod gets yea longer.. And the other rod gets the same "yea" shorter. The wheels move into a position where, if you started doing this with the wheels pointed straight ahead, you'd end up turning right or left, depending upon which way you rotated the rods.

So, I've gotten cars back from a front end alignment with the steering wheel off by 45 degrees. Mumble under my breath, take it back, complain. The mechanic comes out, curses a bit, loosens both tie rod end lock nuts, rotates the rod ends in opposite directions by the same amount, tightens the lock nuts, and see if he did them in the right direction. If he did, it may be close (these guys do do it for a living); if not, he'll be off by twice the angle. Curse a bit more, loosen the nuts again, rotate the rod ends opposite to the direction he did it in the first place, tighten it up, check.. And give the car back.

None of this counter-rotating stuff, so long as the rotations are the same amount, affects the toe-in. But if one does do it outside of an alignment rack, it's a good idea to mark things with a spot of chalk.

KBeck.

 

That's a simple adjustment, a procedure scarcely changed since cars of many decades ago.

MY CPO Prius came with the steering wheel off-center and too much toe-in. Half a turn of the right tie rod fixed both simultaneously.