How to replace pinion gear
 

I recently tried to replace a pinion gear on the Crazy Max 370 motor, with great frustration. As I tried to pull the gear off, I think I damaged something inside the motor as there is now more fore/aft play in the shaft. It still spins freely by hand, though. Now I can't figure out how to get the new gear on! I :confused: tried heating the new brass gear in the oven, but by the time I started trying to put it on the motor shaft it was cool to the touch.
What is the trick? Please include details.
Don

How to replace pinion gear
 

You need a special tool to remove the pinions without damaging the motor. It's called a pinion puller, and many hobby shops that have R/C cars will have one. Instead of yanking against the motor frame, a pinion puller grasps the pinion and pushes the shaft out.

That motor is probably ruined, I'm afraid. :(

To install the new pinion, you can either use a pinion press, or do what I do: Get a hardwood block and drill a hole in it just deep and wide enough to hold the pinion. Position the motor shaft over the pinion, and tap gently on the back end of the shaft using a pin/punch/nail set and a hammer. You may need a helper to hold the motor while you hold the pin/punch/nail set and tap. Do NOT put pressure on the motor case to install the pinion. You'll destroy the motor.

Pinions
 

Yes, you must get one of the Standard GWS gearpullers[@ aeromicro for $12.95]. Get this larger version (not the Micro), unless you intend to specialize with "tiny" motors with 1-2mm shafts. This Standard version will deal with everything from 280's thru 600's and brushless from Razors up thru AXIs and Phasors.

To fit new pinions DO NOT USE A HAMMER

I recommend using a vice as I suggested in this post in the "Motors" thread:

http://www.rcuniverse.com/showthread...ghlight=pinion

Cheers, Phill

How to replace pinion gear
 

If a motor is known to be dead then pinions can be pulled (though it may destroy the rest of the motor!) by putting the shaft in the cleft of a claw hammer and then banging the motor body down sharply on something solid, keep your eye on the flying pinion! To put on a new shaft I use a vice and blocks of softish wood so that they are more likely to get damaged than the valuable motor.

Cliff