Originally Posted by prettyinpink
I havent run my car yet but im thinking its from chassie flex. I run my nt1 few years ago with a carbon fibre chassie and it stripped gears due to flex and it was fine before i made the change. hope this helps but im thinking a thicker chassie is the only way to stop it. But i will see how my car goes later this week.
I think your are wrong mate. i don't think stripping gears comes from chassis flex when we talk about the mtx5. The car doesn't need a thicker chassis it's fine as is man. When the chassis flexes, it flexes in the direction of the engine (when the brakes are applied) so the gears remain in contact, the chassis does not flex away from the engine in normal operating conditions (you would need a shyt load of force to bend the small area at the back of the chassis away from the engine). The chassis flexes from left to right but i am pretty sure this occurs at the point infront of the engine.
There is no point holding the car and bending it as this isn't an indication of how the car flexes on the track, so IMHO, there's no point checking for "flex" like this.
the stripping comes from a poorly set two speed, ie one set screwed in more than the other or the gap being too small, or the two speed remaining engaged when going from 2nd to 1st gear. The issue of remaining engaged is related to the above issue (set screws uneven, or gap too small. The small gap means the shoes remain grabing just a bit and keeping the gears engaged, this is when it can strip).
stripping can also be caused by massive curb hopping. I did a fair bit of this at lilydale so i can say that the gears can take a fair bit of abuse
Stripping can also be caused by the gears being warped. You can warp the gears by screwing in the screws uneven, or into cold plastic. heat up the gears, and or pre tap the holes before screwing in the gear holders. the gears should spin true or very close to true.
Make sure you set the gear/engine gap with the larger spur off. leave the smallest of gaps. just enough so the spur spins without making a binding sound.
make sure the pinions are not worn out or sharp.
finally make sure that the larger pinion is not touching or close to touching the larger spur when the clutch is fully engaged. If the endplay is big enough, a warped gear could potentially grab the larger pinion at some points. Shim out the larger spur if needed.