My scotts tractor s1642 blew the drive belt. There is no information in the owners manuel on how to replace this belt, only how to replace the mower belt. HELP PLEASE.

Some of this might help. I am in the middle of replacing mine and have it all done but getting the belt back over the idler pulley. That is the only hard part. You will have to remove the deck first per your manual (link attached to download one if needed), then the steering linkage, the brake linkage, and the connection to the parking brake lever. Then look at the diagram on the parts listing (link attached) and re-route the belt. Like I said, the tensioner is the most difficult.
Good luck. Also is a link to some other postings.
Greg

John Deere - Parts Catalog
Scotts Tractors - Manufactured by John Deere - Operator's Manuals
Scotts s1642 Hydro Transmission