TA-04 gear question?

[circuitR]

I'm wondering if anyone can help me out.
I've got a TA-04SS and the pinion gear keeps slipping on the spur gear. Every time I nail the gas I hear this loud cracking/graunching sound comming from the spur. I've tried tightening the gap between the pinion and the spur, but it still slips under heavy load.
The guy from my RC shop reckons the bearing may be shot on the pinion, I kinda think it's the motor plate flexing.
Has anyone else with this chassis had this problem?
It is second hand and I am running an 11 turn double.

[Asmenoth]

I've never had that problem with my TA04R. Now the motor plate on that one is the flat aluminum plate and not the finned one, correct? Make sure the screws are tight on the plate and make sure the screws holding the motor in place are tight. I've never seen anyone say anything about a flexing motor plate(doesn't mean it doesn't happen), the bearing problem sounds right. You say it's second hand? Pull the shaft out and check the bearings. If they feel gritty, cleaning them...if they still feel gritty, replace them. OR if they look like hell...replace them.

If that doesn't work get the hop up part for the finned motor plate...it cools better and seems to be stiffer. Also get the aluminum/graphite hop up part for the spur gear. Actually check that as well. The original mounting part may be worn and/or flexing under the load of the 11T motor. I would also go ahead and check the other bearing while you are at it, no telling what condition the car was run in and if they had ever been cleaned before.

[circuitR]

Heya asmenoth,
I've just brought the hop up for the spur gear. Yes it is just the flat alloy plate and I will check the screws on that as well as the bearings.
If that dosen't cure it I guess I will go down the heatsink route