Replacing Traction belt on LT155

[ozziesjoy]

I have replaced the tractor's traction belt (not the mower drive belt, the tractors itself. I replaced it because the power in both forward and reverse had diminished greatly. Now the tractor won't move at all. There seems to be much to much play in the belt and I'm sure I purchased the correct one.
Does anyone have the drive routing diagram? I'm sure I did something wrong (probably simply stupid) but the grass is growing fast and my tractor is standing still. PLEASE HELP!
Serial # MOL155BB137121 if this helps. I purchased it new about 8 years ago.

 

[Baby Grand]

Does it have a thingy in the back you pull out so you can move the tractor without damaging the HST?
Our Craftsman has this and I can't count the number of times I finish a repair and forget to push the thingy back in.
Then I think "OMG, I broke it" until the dear wife reminds me to push the thingy back in.