I cant say on the greenfield as ive never seen one but the Victa i have here has a bit of spring steel in sort of a Z shape thats mounted at one end to the body and the other had a pad on it. When you lift the deck back to dissengage the belt the top of the spindle hits it.
Theres a Greenfield deck on eBay here in Melb at the moment. Might be worth a look at the picture, its got pulleys and things on it still. You might be able to pick up on something thats there that yours is missing.
Cheers, Bob.
