Johannes Erdfelt

So I got an alignment done on my S4 today. It had been about 1.5 years since I last had it done and the steering wasn't centered when the car drove straight.

Turns out it was easy to fix and they only twiddled with the toe.

But I'm looking at the sheet they printed out that shows the alignment and there's a value called "Front Setback" and "Rear Setback", but I don't know what it means.

Any ideas?

mulsannekink

It's how in line each set of wheels is. eg a lawn boy has alot of front set back.

smallTTs

"Setback is an angle formed between the geometric centerline and a line perpendicular to the front axle (similar to a thrust angle, except in the front of the vehicle). The preferred setting on all vehicles for setback is zero. A negative setback indicates that the left side wheel is further rearward than the right wheel. Likewise, a positive setback indicates that the right side wheel is further rearward than the left wheel. If a setback condition exists, the wheel base will be different from one side of the vehicle to the other. Setback usually exists as a result of a collision, frame repairs (cradle shifting) or parts installation, and stacking of manufacturing tolerances. It is important to measure setback so it can be compensated for when measuring individual toe.

Cross-caster readings in excess of 0.5š without factory adjustment, are an indication that a setback condition exists. When setback measurements exceed 0.5š (some light trucks are the exception), it's possible that a component is bent or positioned incorrectly. To check the lower control arms, for example, compare the caster and setback measurements. "


Try a Google search for "wheel alignment" "setback" for more than you ever wanted to know.<ul><li><a href="http://www.google.com">http://www.google.com</a</li></ul>