Uncommon toyota transmission question

[aw10]

I was hoping someone with a significant amount of experience with transmissions could weigh in their thoughts.

Without getting too off subject I have had a rock crawler with a motorcycle motor in it for several years now. I was using a g52 transmission and it never gave me any problems. Went out for a ride one day and broke something in the transmission. ( Will add a pic if the gear because I am not sure what it is ). I purchased another g52 and broke it the 1st time I went out on it. This surprised me because I gave the previous one no mercy when I rode and it lasted for several years. I use the clutch of the bike motor so the toyota clutch and flywheel are just there to be able to mate everything up. When I took the 1st transmission out I noticed the teeth of the flywheel were hitting the bell housing of the trans. I thought the weight of the clutch and flywheel not being supported allowing it to move THAT much was the reason for the break so I had a machine shop make an adapter that weighs a few pounds to replace the clutch and flywheel however it is still not supported like it is when bolted to the back of the motor. Even with the lighter adapter, I broke the 2nd g52 after a little bounce while I was still on the gas when it came down. ( Motor makes 175 - 200 hp, around 100ft-lbs )

I do not know what broke on the 2nd trans because I have not taken it out yet.

My current thought is to buy the R151F transmission with a transfer case on it to make it stronger. Is the motor too much power to even the R151F??

My question is... even with the R151F am I making the transmission significantly weaker by not fully supporting the input shaft on the transmission even though I dropped the weight of the clutch and flywheel to around a 2-pound adapter? Im sure it would be better if it was fully supported but it would take a lot of money to make a plate to do that. Im just curious if it makes a HUGE deal on how it handles the power or if maybe the last trans I bought  just had a hard life before I bought it and that's why it didn't last but 1 ride. Would an unsupported input shaft cause the gear I have circled below to break or is that just becuase it was under too much power? My uneducated guess would be it would break the imput shaft if the main problem came from it not being supported??

This is the gear that broke on the 1st trans



This is the adapter that takes place of the clutch and flywheel. The 2nd picture shows how it sits when it is installed. It does not have the pilot bearing on the tip of the input shaft in the picture but I do have one installed when I was running it. The piece only weighs a few pounds but it's not supported. The output shaft of the trans holds the weight. To clarify, the clutch and flywheel were also not supported and the trans lasted several years.



Thanks for any imput you might have. If its a waste of my time buying the 151 ill probably just part the buggy out and buy something different because I cant justify throwing money in a new trans that isnt going to fix the problem. I do enjoy the buggy though 

[emsvitil]

The input shaft of the tranny is not designed to support ANY weight at all.

The shaft is normally support by the large bearing on the tranny side and the pilot bearing on the engine side.

Without the engine side,  the shaft is going to get a lot of loads and wobbles it wasn't designed for.

The wobble and loads then transferred to the input shaft gear on the other side of the input shaft bearing and went to the counter shaft gear.


Although I would have expected the input shaft gear to get screwed up....