When engaging 4WD the actuator works fine. Once I attempt to return to 2WD, through the switch, you can hear actuator whirl sound but it's difficult coming out of 4WD. Sometimes I have to come to a complete stop, neutral, or reverse to disengage 4WD. Once I'm finally in 2WD, the front ends makes a rattling sound coming from front differential. The LOCK button does not make any sound or go into 4W lock. I can watch the actuator when I push the lock and nothing happens. Any suggestions? I have pulled the actuator from the machine, and the 4WD actuator piston moves in and out fine, but the LOCK actuator does not work at all. TIA.