My drive belt broke and I am trying to replace it but I need a routing diagram do I know how the new belt goes on.

Try this

Hello, I just had to replace my belt on a 245, which is the same tractor with a smaller engine. Here are some tips:

After you remove the mower deck:

Feed the belt over the fan on top of the transmission and on to that pulley first. It's a little tricky, I found that placing it under one fan blade and then rotating the fan by had was the easiest.

You now have to remove the PTO/Clutch / Pulley assembly. I removed the screen & guard on top of my engine and place a large socket & breaker bar onto the nut and braced it against the battery. Remove the bolt & washer holding the PTO on. The PTO should drop down. If never removed before, you may need to gently pry it off.

Per the diagram above, feed the belt through the metal hanger on the straight run to the engine pulley, then get as much tension on the belt & put it on the front engine pulley. Remove tensioner spring. Lastly, remove the belt guard on the tensioner system. 2 nuts on the pulley axels hold it on. Feed belt per diagram above. Replace guard, reinstall PTO ( I recommend thread locker on this bolt (red Locktight). Drive mower to make sure everything works, if yes, reinstall mower deck.