Originally Posted by
Sean Cochran
I use rear axle width as chassis tuning adjustment. On high grip carpet tracks I run the rear as wide as the tech box will allow. The rule book calls for a maximum width of 172mm. When there is less grip and I need more rear traction I narrow the car a little. To answer the question regarding the kit shims placing all the shims on the right side (spur gear) will get the axle close to centered.
Just order yourself one of these. It is the best $25 you'll ever spend on a 1/12th scale tool.
http://www.niftech.com/catalog.php?mode=3000
And Mr. Cochran is correct. While it is very important to have the chassis centered in the car's track, being able to alter the rear track on the car for high bite and low bite conditions is very useful in getting a 1/12th to handle properly.