Scag Rattles after startup

[tim4]

I am working on a scag z mower and when it is running I get a rattling sound but it is not from the engine. The drive belt shows sign of wear on the wide part of the belt. How do you access the top drive belt pulleys, there is no room underneath?

 

[7394]

A suggestion for the rattles, wiggle the hydro "dump valves" one at a time..They are metal & do make a rattling. I zip-tied mine to be quiet & they have been ever since..