I know im dumb abusing the 240(non turbo) anyways,
i have broken 2 m47 gearboxes first one i only blew the 3 gear. But the 2 one was kinda weird,
i was reving the engine up to do a 1 gear burnout and when i dropped the clutch i blew almost all the gears in 1 go, all im left with is 4 gear. Ive head that 3 gear is a weak point but never have i ever heard of someone blowing up 1,2,3,5 and revers in 1 go? Can anyone explain this and why?

 

i'm no expert but once one breaks the pieces have to go somewhere. into the rest of the gears sounds likely.

 

Here's a diagram of the insides of your transmission. The laygear in the bottom of transmission is used for gears 1,2,3 reverse and 5th. 4th gear is "straight through". The laygear is one big part. So all those gears on the bottom spin together. Gears on the top row can spin independently (of each other on the top row) giving you 1,2,3,5 and reverse. The m47 has an aluminum case and is a "weaker" trans than the m45/46.

So you broke something related to the laygear - Maybe the teeth off of the small input gear.