so my mechanic told me that u can use motor oil on your tranny and i know that sounded strange so i wanted to make sure has anybody ever tried that

 

You can and honda has also said you can. I run nothing but syncromesh friction modified but it's all opinion. The GM is part synthetic I hear so it doesn't break down like the motor oil would, but in a transmission I would assume it would still take a lot of miles compared to in an engine

 

Honda transmissions were originally designed to be run on motor oil, so the answer is yes, you can. This is also the reason why you MUST NOT run GL4/5 Synthetic Gear Oil in your Honda transmission (i.e 99.9% of performance gear oils on the market) as it is too thick. You must stick to low viscosity transmission fluid.

However, motor oil lacks the additives required for longevity, hence why Honda released their custom transmission fluid to meet the requirements (MTF).

The GM/Pennzoil are also very good transmission fluids to use, but I personally use/recommend Torco MTF.