recently all of my recivers (603ff and 603fs) have been going into a slight reverse position every time I turn on my radio when its at neutral this is happening to all of my electric cars. I've reset the end points but it just keeps happening randomly. am i doing something wrong?

You may be experiencing drift. It's a normal thing to happen to any transmitter with age. The potentiometers in the transmitter start to wear and the radio needs occasional re calibration. Go to page 102 of your 3PKS owner's manual, it will give you step by step instructions on how to re calibrate the transmitter. I've done it before on my 3PK, it's easy and usually helps the problem.

Try to rebind it.

Before you adjust them check how far out they are. If they're 15% or more off center it's time to send it in for new pots. Sprague is correct though, if they're off a little you can adjust them back to center and that should correct the problem.