ooldguy93

I've got a '16 Z06 attempting to get a " track alignment "

I've, so far, visited 3 Chevy Store Service Dept.'s that sell and
( hopefully ) service Corvette's

None, so far, are familiar with the special tools that are required to adjust the rear caster or have even done a C7 alignment

Has anyone any experience with a Chicagoland Chevy dealer that is knowledgeable

thanks,

Robert Dudek

thebishman

Robert,

Isn't it amazing that this many years after the C7 Z was released dealerships don't have the necessary equipment needed to give an owner a decent alignment? I guess the actual term I should use is pathetic. Some still don't realize that you can and should adjust rear caster on the car.

I would check with your local Corvette; Porsche; BMW clubs in the area and find a local specialized 'race' shop that owners who go to multiple HPDE events go to for service/alignment issues. They'll do such a better job than the dealership would anyway.

Bish

'12GS

Caster measurement requires turning the wheels. The only way to do that in the rear would to be disconnect the tie rod ends from the spindle. Not sure that any regular shop is going to go into that depth for an alignment, especially because rear caster will make little effect on handling.

juanvaldez

Not true. Caster on the C7 is measured directly using a couple of special tool, a little fixture that attaches to the rear knuckle into a couple of holes and a magnetic angle measuring thingey.

davidfarmer

all you need is 2 1/4" bolts and a level (even a smart phone). GM made it super easy once you know what to look for.

Bring it to NC and I'll get you squared away!

Bill Dearborn

The first thing you have to do is make sure the person you are talking to has some sort of knowledge about the car and the Service Writer standing at a desk in the greeting area of the shop isn't the one who knows. The rear caster requirement and directions on how to measure it are clearly defined in the Factory Service Manual which the mechanic can look up at his work area. There is also a TSB #16-NA-056 Dated Feb. 22nd, 2016 which addresses setting the track alignment on the Z51 and Z06. They can also look this info up on the PCs sitting at their desk just like the mechanic that gave me a copy did.

GM will loan the dealer the tools if they don't have them. The dealer I use didn't do the alignments and when I asked the Corvette Mechanic looked up the info and told me he could do it but they don't have the tools. The shop foreman who orders the tools for the shop refused to spend $1000 for tools to support one car. That is when I used the forum to ask Tadge a question about the issue which he answered. You can see his answer here on the forum.

It isn't easy to set the toe when the DSC rear caster and camber settings are used. The toe links don't have sufficient adjustment and just as you get close to where you want to be the adjustment reverses as you turn the cam. That usually means more labor hours are required to get the settings where you want them and that can add to the cost of a normal alignment. Getting to the GM recommended 0.00 degree caster settings isn't that hard since the toe links have the range to get the proper toe.

I do my own alignments and have purchased the GM Adapter along with a 0.1 degree accuracy/.05 degree resolution Wixie saw blade angle gauge. Total cost of both tools together was about $220.

Bill

Bill Dearborn

With the tool GM uses in the rear you could measure front caster without turning the wheels. It is based on measuring the angle of the knuckle in reference to a true vertical baseline. The turning of the steering wheel does the same thing by measuring the change in camber angle and then calculating the caster from that measurement.

Bill

ROBMARZ

Bill, do you have the part number for the GM Adapter?

davidfarmer

you don't need a special tool...there are 2 holes in the knuckle, just install 2 bolts and hold your level against them.

Nowanker

Thanks for the tip!
I don't presently have any C7 customers to do an alignment for, but I'm always happy for the info.

BrunoTheMellow

Yep. Just get two 2" long 1/4" bolts or tubing, or w.e. Then a flat piece of metal and a magnetic digital angle gauge. Very simple. Took it to a local porsche shop and after they said they didn't have anything, I just let the guy use what I had.

Bill Dearborn

It is CH-47960-10. The GM gauge is CH-47960. You can order them from the following service tools organization:
https://gmtoolsandequipment.com/en-U...KU=CH-47960-10

The saw angle gauge I use is the Wixie Digital Angle Gauge (WR300 Type 1) that has +/- 0.1 resolution and +/- 0.1 accuracy. The gauge has been discontinued and replaced by the following gauge:
Digital Angle Gauge with Level (WR365) which has the same capability but also includes an analog level. When choosing the gauge you need to be careful not to order the ones that have an accuracy of +/- 0.2 degrees as the rear caster adjustment range is only +/- 0.8 degrees and a +/- 0.2 degree accuracy tolerance is basically a quarter of the range. Nothing like making a measurement with a tool that has built in guaranteed 25% measurement error for what you are trying to measure.

Yes, you can use two bolts but sometimes that doesn't work easily. When I am measuring rear caster I have the car on the garage floor and I crawl under the rear of the car to make the measurement. There isn't a lot of room for my body and I can barely reach the knuckle to install the adapter. Then I zero my angle gauge as GM says to do and magnetically attach it to the adapter. Once it is attached I remove my hand which has been blocking my view of the gauge, shine a flashlight on the display and read the caster number. If I used the two bolt method I would need to hold a gauge up to the bolts but wouldn't be able to see the gauge. Also I wouldn't be able to use the gauge I am using since it isn't long enough to fit across both bolts.

Bill

RoketRdr

You have no idea what you're talking about.

Nowanker

That's a little brutal...
Standard F wheel alignment techniques do utilize the 'wheels turned' method...
And I'd be very curious to see just what effect it has on handling. It's more for stability on the F, but then those wheels are free to swivel.
Anyone actually experiment with different settings?

Poor-sha

It changes the toe curve in the rear as the suspension compresses. DSC measured the curve to come up with their recommendation. Many threads on this.