I have a john deere lt155 , I just replaced the traction belt. Drive belt or what ever it is called. I followed the pictures on line. Also replaced the spring. But now nothing. Seems the belt is to long but I saw some older posts on line with the same problem, but no answer. Someone help please.

Does it look like this ?
Did you get the spring # 14 hooked in the right place ?
Does the bracket with pulleys 31 and 32 swivel back and forth ?
Is the flat side of the belt against idler 31 and the v in 32

It does look like that, that is the break down I found and used. Only difference is the pulley close to the side that the spring goes under does not look as far to the front as the break down looks like it does. I didn't move it from it's original location so it has to be right. I'm not looking forward to taking this all back apart is there a chance John deere sold me the wrong belt?

Very possible , wouldn't be the first time that happened .