Craftsman Model 917.276903 rattle in undercarriage

[RL9144]

Hello,
I have the mower referenced in subject line (Craftsman Model 917.276903) and am experiencing a rattle which sounds like a rod knocking in the undercarriage. When I even slightly put pressure on the cluthc/brake pedal it stops. This does not appear to interfer with the mechanical functioning of the tractor at all but is grating on my nerves. Any suggestions?
Thanks,
RL9144

 

[Fish]

With engine off, see if you can get some movement from wiggling the engine, as the mounting bolts may be loose.

Also look at the belt to your trans, the belt may have a chunk missing off of it.