Originally Posted by Twangmaster

You'll need to set the steering up with the radio.
Take the servo output arm off the servo by removing the servo output screw, but leave it hooked to the steering linkage. Find out where the servo arm wants to set (align) with the front wheels pointed straight ahead. You're probably going to check this several times, so take note. Now, without the servo output arm off the servo, turn on the transmitter, then the radio in the car. Check and make sure that the trim on the radio is centered. If it's a programmable radio, check the radio manual looking for a 'sub-trim' or similar adjustment on the menu. Check that, making sure that it is at '0' (or whatever it's supposed the correct value for your system is) and that the endpoints for both directions is set to 100%. Now, with everything centered, the servo, the software, and the front tires, put the servo output arm onto the servo and re-install the screw. Check the steering each way to be sure it's:
1) Equal on each direction and each tire
2) It's not too much (hitting the suspension or binding) or too little.

You can now adjust the transmitter endpoint adjustment to equal out the steering.