I am sorry Roger but I cannot visualise how a pinion does not fit a motor shaft and spur gear on a TC6.

Maybe make a pic of your pinion?

and I am running on long sweeping tracks also, 2 different ones , one even more 1/5th scale than 1/8 1/10 scales ic and 7.57 is very good and fast.

ok, will try 7 when ill be on the track. About pinion will do pics evening.

I am pretty sure this is a motor problem...I used to have issues with this with some of my speed passion motors a while back. I think some of the screw holes are not tapped very straight...trying turning the motor and using other holes if possible.

Yeah, this was an issue for a very short period of time. All fixed with the new batches though.

maybe guys, but that is only on few pinions, xenon and kawada pinions are ok. they fit no problems because xenon have 4 holes and they are thinner on head, same with kawada.

I saw on my friends car, LRP motor, PRS pinions, that the shank on the pinion was long enough that it didnt sit on the flat spot of the shaft. You would have to dremel the flat spot back a little bit farther. I seem to recall some issues like this a while back with Duo motors as well.

that is only with 3 pinions what i have, so i thought easier will be order different pinions like xenon and i did it so the problem is sorted

thanks to everyone for help!!!

With some pinion/motor combos, you have to either chamfer the end of the pinion, or cut the shaft flat spot back farther so the pinion will align with the spur. This is because the motor is so close to center for great weight balance.

There is no need for this modification if using a Reedy Sonic, or LRP X-12 motor.

Yo Karl - u done with your car yet? Its been two hours .. what is taking so long?

You wont find him on here for a while, hes deep in the middle of nowhere in MD surrounded by various wrenches, greases and lubes...

Hopefully he can show tomorrow at Jackson.

Mike - when r u coming out again?

He will be there tomorrow fo sho. 50-50 chance I'll make it next weekend, but I will 100% be there for nats (only 2 weeks away!?!?).

My Brother had the same problem. If the pinion was properly lined up with the spur, the grub screw on the pinion would not tighten on the flat area of the motor shaft. Naturally he didn't want to buy another motor with a longer flat machined on the shaft or locate another pinion with a different offset that might work. He brought the motor to work and machined the flat on the shaft long enough to allow the pinion grub screw to tighten on the flat.

can anyone tell me the dimensions of the hubs bearings? (bearings holding CVD in read hub and steering cup) and size of diff ball?