I replaced the drive belts on my Troy Bilt Pony Lawn Tractor. There is a spring that goes from deck toward back of mower (about 8-9 in). I know where it connects to the deck, but where does it connect on other end?

Hi,
Often it is a hooked backet attached to the lower side ( one of them) of the transmission. Usually painted black and roughly "L" shaped.
Peace,
Clarke