I rebuilt my TRX a few weeks ago. I thought I had a clutch problem so I pulled the cover. I found the snap ring had come off of the oil pump and the chain came off! Thank god my new crank was not damaged. I have a slight knock when it is at idle (had this before). Everything was put back on with a new snap ring. Now in 5th gear at med to high speeds it sounds like a drive chain slipping. Ther is no drive chain on the TRX! It only does it in 5th. If you put it in any other gear and lock the brake it will not make the noise (rules out rear end. I took it all apart and split the cases this afternoon. I cannot fing anything broken in the transmission. I do have a loose oil pump chain. I am ordering a new one as well as piston kit Monday. Any ideas. Please no wild guesses. I have a great deal of experience with my motocross bikes but not this TRX. I just cannot think of a thing that would cause this types of noise and slippage in 5th gear only!

 

Did you have the transmission apart or did m5 fall off the mainshaft .. ?

 

Yes, I rebuilt the crank. You think it may be in backwards?

 

Yes, I would say a gear is flipped. Where it meshes on the side of the gear is where you are hearing the sound from because they are not totally meshing

----- Gimpster -----

 

I guess its possible or the washers are swapped.

 

What are you thinking? Swapped or washers reversed? I am lost on this one. I really liked this 4 wheeler but may just sell it after I get it together.