Can my Lawn tractor take a stronger Transaxel?

[eseemann]

First time post and I must say I really enjoy reading what has been posted here. I have a Craftsman lawn tractor 917.272751 18hp. I think I have over used it a bit harder than I should have. When the mower is in gear I hear a tic tic tic tic coming from where I figure the transaxle is. I figure that I will kill it sooner or later and need to replace the part. The direct replacement is a Peerless # 206-546. This is about a $250.00 new part but I wonder if I can get away with putting a medium duty in to replace the light duty peerless. Any thoughts?