1994 z71 chevy k1500 please help
 

my truck run just fine but 1-4 gear work just fine but neutral and rev are not working right when i put into neutral it acting it is in drive also when i put into neutral cant put in to 4 lo even with the truck is off and then with rev it go forward for a second and then stop hard then i put throttle to it nothing is happening no rev at all and park is just fine workers perfect