Going Straight or Dogtracking?
Sunday, June 1st, 2008I have seen a couple questions from folks wondering if their car is dog tracking and if the frame on their car or truck is damaged, bent or not straight. There is very simple test nearly anyone can do at home to check if your vehicle is tracking straight. In the body shop they talk of a frame being “diamond”. In other words, if a car or truck with a frame is hit on one corner, in the direction of travel, the frame rail on that side can be pushed back compared to the other side, leaving a diamond shape to the frame. A misshapen frame affects the relationship of axles and wheels.
Here is how you can check your car for tracking straight. Hose down a section of pavement with water and then drive through the water and beyond for a car length or two. Get out of the car and go back to see what the tracks look like. If your car is tracking true, the rear track should be centered on the front tracks. Usually, the rear track is slightly narrower than the front. I made a couple of simple drawings to illustrate this.
In the example of a damaged frame, the left side frame rail is pushed back which causes the solid rear axle, (as in a pickup or rear wheel drive car), to point toward the left instead of pointing in the same direction as the frame center-line. When driving a vehicle like this the driver must steer to the left to go straight down the road. A giveaway is that the steering wheel is off center.
There are other conditions that can result in dog-tracking, which I will address in a later post.