I have a 60'' mower on a 3225 cub cadet and I need to know how the belt goes back on the mower deck. Is there a diagram online to see which way the belt goes around the pulleys.

That will depend on the model of your mower. Generally you have to remove the deck and deck belts. The drive belt usually goes from the engine pulley to the transaxle pulley. There may be a tensioner pulley as well that keeps the belt tight.

Changing the Blade Drive Belts:
a.Set the parking brake. Remove ignition key and both spark plug caps.
b.Unscrew the wing nuts from the deck covers and remove both covers.
c.Using a 3/8" socket breaker bar or socket ratchet insert the drive end into the 3/8" square opening in the lower idler arm assembly and push the idler arm counterclockwise. While holding the idler arm back, loosen the blade drive belt from the pulley and slide the belt away from the pulley.
d.Remove tension of the PTO belt by moving the belt tensioning rod. Loosen the belt retaining bolt.
e.Pull the tensioner pulley away from the belt and remove the PTO belt then remove the blade drive belt.
f.Reverse the process to install the belt.

Attached is the blade diagram for correct placement of the deck belt. There is some bleed through from the back page, but you can see the direction of the belt. I have a 1525 mower for the last 11 years, still running and going. Hope this helps!

There is a site that I use frequently. Go to Partstree.com and enter your model # then look up the diagram. Usually there is a digram on the deck .

this may help Tim:

http://www.ehow.com/how_6182447_remove-mower-deck-cub-cadet.html

if you go to cub cadet.com click on info center tab then owners manual put model and serial number in it will show you a diagram

Type in your model number to your search engine. find your model, and your diagrams will be there.
hope this helps.

Go to this website, upper right hand corner and do a parts look up. Search for your model and that good stuff they ask of you and then choose mower housing should be there, browse the site it's really cool and has a lot of info.
http://www.jackssmallengines.com
I did a sample search for generic riding mower deck and found great diagram of belt routing. Give it a try you will find same results Good Luck! Don't forget the thumbs!

Visit this web site http://www.partstree.com/parts/
you can pull up your Cub

Try this one. It may have what you're looking for. Without your model #, I don't know.... http://www.partstree.com/parts/ Click on Cub Cadet then enter you model # on the left.