Dealer Alignment Question

Familiarize yourself with the term zero-point calibration, of the steering angle sensor.

This is a video on how Hunter codelink works:

Hunter CodeLink® - The New Last Step in Alignment Service

 

What are the symptoms of zero-point calibration being off?

 

Front toe-in at zero or .1?
This has been a very helpful thread to read. I have a question for xs650 and The Critic concerning toe-in for Gen. II (mine is a 2007). In John's unofficial Iconic Prius guide, he specifies a front toe-in of .05 per wheel for a total of .10 (John wrote that this was frequently recommended over PriusChat). Toyota's spec is apparently zero (0) on all these specs. I've recently had my 2007 aligned to the .10 total spec (along with new tires, Michelin Defender) in hopes of improving stability at highway speeds. It seemed to help, though it's possible the improvement is due to the amazing new Michelins that replaced Goodyear Integrity! Would there be any disadvantage to toe-in at .10, such as increased tire wear or decreased mileage? This assumes all other alignment specs are OK (I'm attaching the post-alignment readings as done by my local Toyota dealer). Thank y0u, Bill in Ypsilanti

 

0.1 total degrees toe in is a very small amount of toe. I think you would be hard pressed to feel the difference between that and 0. If you could feel the difference it would be a little more stable. Difference in wear is also probably undetectable outside a lab.

 

Thanks very much for the reassurung words, xs650--this is a subject I know next to nothing about, aside from what I've read here. The front toe-in does appear to be within specs, according to the graphs on a second post-alignment readout.

Do you think the .30 degree toe-in on the right rear is cause for concern? It appears to be out-of-spec (shown in red), even though the total toe is apparently OK at .44 degrees. Can toe-in be adjusted at all on the rear?

My rear toe-in looks similar to that posted by Aaron earlier in this thread, though my camber is apparently within spec.

From this thread, it appears that rear readings can vary simply by how the car is driven onto the rack, so this may not be worth worring about.

Thanks again--PriusChat has been extremely helpful ever since we bought our 2007, which we love as much today as when it was new!
Bill

 

Rear toe can be adjusted with shims. That has been covered in a few threads. One of the common brands is garbage, so do some research with search. Michael, "the critic", here on PC has experience with the garbage brand that smashes to pieces and he also found a brand that works.

The most important dimension on rear toe is the total toe. It will stay pretty constant as the car is driven off then back on the rack. The rubber mounts allow the whole axle to rotate a bit so individual left and right rear toe varies a bit, but not total. IIRC, the good shims come in 0.25 degree increments. If you added one to the right rear, then you total rear toe would be 0.19 degrees which should improve tire wear and fuel economy a hair and might reduce stability a hair but you might not notice any of those difference...or you might.

One rule of thumb for decent alignment work is to cut the factory tolerances in half. For total rear toe, the factory says 0.29 deg +/- 0.3 degrees. If you reduce that to 0.29 +/- 0.15 degrees the limits would be 0.14 to 0.44 degrees. 0.44 deg sounds fairly good that way.

If it were my car and I had the alignment checked ( I haven't) I would probably stick in a 0.25 deg shim, more for the satisfaction of doing it than expecting a big difference.

For some truth in blathering..... On my other car that takes a $1400 set of tires and has fully adjustable suspension, I went to a performance shop, had a discussion with their top alignment tech (the shops so-owner) and got the car aligned to his recommendations after he learned what my driving style, handling and tire life preferences were.

Unfortunately that shop is getting out of the car business but I just found a local NASCAR/NAPA shop in Roseville, California that builds NASCAR cars and does all sorts of performance car work for less than dealer labor rates.

 

I had my car realigned under warranty at the dealer. It took two tries to get it right. So I have been doing some research on my own...

I was reading the 2010 Repair Manual's alignment section. It calls for the VSC Yaw Rate, Acceleration sensor to be re-zeroed, after an alignment, not the steering angle sensor. Furthermore, the manual seems to indicate that the steering angle sensor recalculates a new zero, every time you drive above a certain speed. It it drifts too far from the previous value, it will trip a warning.

Can anyone confirm my understanding? Does Hunter's procedure not work for this car, or, it is just another way to accomplish the same thing, since these two sensors need to agree with each other so one of them needs to be re-zeroed?