look behind the right front tire there will be a round shifter motor with a plug on the side, unplug and clean with a electrical cleaner and put electrical grease on it.This should take care of the problem. If not you may have to remove the shiter motor and take it apart and clean the contacts and the armiture. Its easy to do it takes about 15 min to take off and take apart the motor to clean. If that does not work it cost about $70.00 for new motor. If you do replace you need to replace the gear behind it for about $15.00. This is an easy process also, just remove the 3 bolts on the cove the motor is bolted to and remove the gear.