C2 & C3 rear Tow- in alignments.

[William V.]

Is there any information on how much tow changes could be expected when a shim is move from the one side to the other on the rear trailing arm? (1/32nd or 1/64th shims)

Thanks

Bill

[Duke W.]

Re: C2 & C3 rear Tow- in alignments.

The change in rear toe will be proportional to the ratio of the tire radius to the trailing arm swing arm radius.

I don't have the dimension for the swing arm radius, but it is greater than the tire radius. If anyone has a loose trailing arm around maybe you can measure the distance between the center of the bushing and the center of the hub. Tire radius for OEM tires is 13.5 to 13.7".

Thus, if you swap a shim, say 1/32" from the outside to the inside or vice versa, it should change the toe measurement on that wheel somewhat less than 1/32". It will also change total toe by the same amount.

The important issue when setting toe on the rear is to get it equally divided between both sides. This can be accomplished on modern four wheel alignment equipment since it measures toe on each wheel and computes the out of alignment of the thrust angle.

You can set toe in your garage too, but you must carefully measure the true centerline of the car - string it with bobs, and then set each wheel relative to the centerline. It's easiest to do this with the body off the frame, but can be done with the body on the frame.

Duke

Duke

[William V.]

Re: C2 & C3 rear Tow- in alignments.

Duke

Thanks for the info.

I have 3 cars to align and I will estimate the shim change equals the tow change. This is not exact but should help avoid some trial and error.

Bill

[Patrick H.]

Toe-in. *NM*

[Ronnie Robertson # 36786]

Re: Wheel Alignment 101.

Duke,

What exactly is meant by "setting the toe in so it is equally divided". It seems that if each side can be indendently adjusted- how does it effect the other wheel?
Ronnie

[Duke W.]

Re: Wheel Alignment 101.

One the front end we set total toe between the wheels. When driving the toe will automatically equalize, and if it's not equally divided the steering wheel will just be cocked at an angle. This is corrected by tweaking the tie rods as necessary so the wheel is straight when driving in a straight line.

Let's say we set the rear total toe at 1/16", but you don't know if it's 0,1/16 on each wheel; 1/32, 1/32; or 1/16, 0. If you get it unequal enough the car will "dog track". A small amount of unequal rear toe may not result in obvious dog tracking, but if it's not equally distributed the car can pull under accewleration or not handle the same right of left. It just won't feel "right", but unsettling.

Duke