My car tends to pull to one side or the other, how do I get it to go straight?
If your model tends to pull to one side or the other when you're driving, it could be caused by any of a series of problems. This article will discuss the very basics of setting up your car's suspension.
To start, make sure your car's steering servo is centered in its range of travel, and that the steering trim on your transmitter is centered. Also make sure that the steering wheel on the transmitter is centered, and easily finds the same center every time you release it. If it doesn't do this, you may have to return your transmitter to its service center for repairs.
Then, make sure both the front and rear wheels are straight, so that the car's front and rear wheels track in line with each other. If they're not straight, then the car will track with the rear slightly to one side or the other. Along with this, make sure all wheels rotate freely. The car will pull towards the wheel that's not turning freely.
When the car will track straight, adjust the front wheels so that they have about 2 degrees of toe-in. This means that both front wheels point inward from front to rear. The toe-in must be equal on both sides, otherwise the car will pull towards the side with less toe-in.
Once the wheels are set up, inspect the chassis. It should set dead level from front to rear and from side to side. If it doesn't do this, you'll have to adjust where the shocks bolt onto the shock towers and the lower suspension arms. The shocks should bolt exactly the same way on the right side as they are on the left side. They can be different between the front and rear suspension. Adjust the upper suspension arms so that the wheels are exactly perpendicular to the road surface. Now adjust the springs on the shocks so that they allow the chassis to be level.
Finally, make sure all of your tires are really round, and that the two fronts and two rears are the same size. If one tire is worn more than the other, the car will tend to pull towards the smaller tire.
If you have the suspension and chassis setup so that the car is level and the wheels are all aligned properly, and the car still pulls to one side, you need to check the drivetrain. It's possible that one side or the other is not putting enough power to the drive wheels, or something's sticking. In this case, you'll have to carefully go through the drivetrain to see where the binding or looseness may be.