XRAY - Model racing cars

How can I make the M18 drive straight? Mine keeps on slowly going right or left.

That could be caused by many things. From loose steering connections, loose front diff, bearing going bad, tires with more grip, a tweaked chassis, to finally a servo going bad or needing new gears.

Make sure all the steering connections are tight, the front diff works correctly and if a ball diff tighter than the rear, the chassis sits flat when its at ride height. For the servo from the transmitter turn the front wheels and let the transmitter recenter. See if the servo recenters itself. to the same position everytime.

Check to make sure your steering linkage is free. With the horn disconected, Center your radio or trim. re install the horn. Also check if your front wheels are toed-in slightly. If not, Xray has upgrade to do that.

You should also be certain that you're using the proper servo arm on your servo, otherwise you may find your car wandering left or right.

first chek as geezatech,and mini me stated. then disconnect your mortor and check the car for locked up or hanging bearings. with motor disconected roll the center shaft and see ef one wheel stops b4 the others. a sligthy worn or dirty bearing will make the car turn sligthy on accelrations.