Yeah you're right but also this transmission has to be stopped and it never will stop so it works properly if the rear brakes work which they did not because they were full rust and the rear brakes break the transmission not the rear axle which transfers power to the rear axle through the chain and the gears I think you get it by now...
slap a twin snowmobile engine in the Polaris Trail Boss she will be wild we have a 2000 Polaris Trail Boss 325 with a Yamaha 570 twin snowmobile engine she's wicked like a banshee with more power
The rear brake didn't work which is the reason why the transmission would grind so much because it's a transmission break without the rear brake the transmission always spins