when put into 4x4 front wheels won't engage and you hear a slight grinding motion.could it be the servo or in the differential?i took the servo motor off and when button is depressed the little gear on it does turn,you can also turn it by hand but there is quite a bit of spring pressure.also what is the proper method for re-installing?does the little sliding bar in the diff have to be pushed all the way to the front?back?rotate servo so it's under pressure?please help and thanks.

 

Look into this. http://forums.atvconnection.com/yama...cheap-fix.html

 

You might have blown your front diff. Ive blown my back and front diffs. $2000 for both! 1000 bucks a peice!