RussC243

Hi,
I want to measure and set my front/rear toe/caster/camber on a 17 Z06. I have a pretty good idea of the desired settings, the basic tools/procedures to measure and an understanding of the level of accuracy I can expect. I am doing this in my residential garage with just a floor jack so it will take a few iterations.

I need info on the following:
-C7, Z06 specific sources of information showing where to add/remove shims, adjust cams etc. to affect the settings.
-how may shims affect how many degrees so I might reduce the number of times I need to take off the wheels, adjust then roll it back to the leveled pads in the garage.
-Where to get the shims? MacMaster Carr ? Shim kits specific to C7 Z06?
-torque recommendations (not necessarily specs)on the various bolts involved? Lock tight?

Thanks,
Russ

c5racr1

It uses camber bolts on the lower control arm. There are 2 shims on each upper control point, Gm recommends removing 1 to get to -2.0in the front, I think the back can die done without removing shims, however rear caster must be set using a special tool. Do a search it has been discussed in depth.

Bill Dearborn

Here is what you need to know.

















You will also need a caster/camber gauge to do the front alignment (which also means having a way to mount to the wheel), a level area in your garage so the car is level from side to side, you will also need toe plates, a 2 ft long digital laser level (Craftsman is excellent) and some jackstands and a measuring stick you can tape to the jackstands. When you get rear toe set you place the jackstands next to the front wheels and place the measuring stick between the jackstand and the center of the front hub. Then using the laser level placed across the middle of the rear wheel aim the laser at the measuring stick and record the measurement. Do the same on the opposite side of the car and adjust rear toe back and forth to make the measurements from one side to the other as close as possible. Usually getting within an 1/8 inch is good. This sets your thrust angle. When setting front toe lock the steering wheel into the straight ahead position and set the toe close followed by reversing the laser measurement by aiming the laser toward the rear wheels with the measuring stick touching the end of the axles. Once you have the measurement equal from side to side and have the toe setting you want the steering wheel will be straight ahead when you drive down the road (if steering pull is minimized by getting cross caster/camber adjustments as close to zero as possible).

The gauge is the same one GM recommended dealers use to set rear caster on the Pontiac Solstice and Saturn Sky. The tool was designed for them so the adapter wasn't required at that time. Reading the maintenance documentation for the two cars it seems the layout of the rear lower control arms made adjustments to the forward cam on the lcas impact caster more than camber and adjustments to the rearward cam on the lcas impacted camber more than caster. I don't know if this holds true on the Corvette but it might be worth experimenting to find out. If so it would make the adjustments easier.

The shims used by GM look like washers but are not washers. They are flat (not tapered) and have a plastic insert in the center hole to hold them on the bolts that hold the upper control arms in place. On the C5 and C6 one shim affected camber by about .4 of a degree, it might be the same on the C7. You can use the older horse collar style alignment shims as well. If you have a Harbor Freight near you that is as good of a place as any to purchase them.

If you make a lot of adjustments over time then you want to swap the uca bolts for studs so you don't wear out the threads in the frame. They weren't designed for multiple loosening and tightening of those bolts per week/month/year.

Bill

RussC243

Bill,
Great info.. That should be just what I needed
Russ

RS4EVA

Thanks Bill, that is awesome

glass slipper

If you go to this link:
http://www.cultragfactoryparts.com/c...4/?parent=1001
You'll see when you draw a line from one rear control arm bushing to the other bushing, then to the ball joint, and finally back to the bushing you started at, you've just drawn an isosceles triangle where the distance from either bushing to the ball joint is the same as well as the angles. The amount of caster change is the same whether you adjust the front or rear eccentric, the same thing for camber...neither eccentric affects camber or caster more than the other. The correct way to make the caster adjustment is to adjust both eccentrics the same but in the opposite direction, this causes zero to negligible impact to camber. The correct way to make the camber adjustment is to adjust both eccentrics the same and in the same direction, this causes zero to negligible impact to caster. Done this way, you can adjust camber or caster first, it really doesn't matter. Of course toe is adjusted last as both camber and caster adjustment affect toe although caster should have minimal impact to toe if adjusted as stated above. For cases where you've run out of adjustment on one of the eccentrics, the above doesn't apply...you're forced into an iterative process.

You can see the front control arm geometry is closer to a right triangle. In this case, the front eccentric affects camber more and the rear eccentric affects caster more with each having a small impact to the other setting. The front caster and camber settings are an iterative process although an experienced alignment guy should be able to hit it in one shot. After a few alignments, I'll know how much each affects the other and in which direction, I can then overshoot/undershoot the first adjustment depending on what my second adjustment is.

RussC243

Thank you gentlemen. GREAT info!!!