Manual needed and repair info

I am working on a older Cub Cadet for a friend, I can't seem to find a manual by model/serial number
 
The mower runs but wont move, owner said belt broke and when new belt was installed it wont move now.
Anyone had this issue or know the repair solution.
 
Cub Cadet
Model: 14D681100
Serial: 8D6625
MFG. Date: D040G