Teacher

I have a HPI savage that belongs to my wife. I havent driven it in several years and i want to get it back going. The truck wont go forward when you throttle it. When you spin the pinion gear backwards the tires move but when you spin it forward it does not does anyone have any experience with this problem. thanks for the help , Thanks for RC Universe giving this site for people like me .

BudBud

I am guessing you are talking about the spur gear between the engine and transmission. That is the way it is supposed to work. The transmission has a one way bearing that allows the truck to coast, yet accelerate under power. Do you get drive to the tires?

BudBud

Back to add turning the top of the gear to the left when behind the truck should drive it forward.

Teacher

i havent ran it in years but i remember the truck would not move when you push the gas. I was thinking back then i read about a posible bad one way bearing. it is the metal gear between the motor and tranny its not the gear the comes directly off the engine , I have the engine completly out thanks for the quick repsonse.

BudBud

If I were to bet, I would bet on the slipper clutch being too loose or burned out. It is easy to check, just roll that spur gear and watch where the movement stops. Next would be the grub screws in the transmission yokes and differential yokes. Then I would check for blown differentials, the last thing I would expect to completely fail is the transmission one way bearing, unless somebody filled the transmission with grease or oil. If te truck has reverse, that has always been prone to failure. It is an add on module at the rear of the transmission. If it has reverse, it will have a third small servo between the steering and throttle servos. It will be installed from the bottom. Glen