Oil leaked from transmission on zts7500 Craftsman zero turn mower. It leaked quite a bit over nite. I used it pretty hard the day before. I cannot find a fill plug on trans. My owners manual doesn't say any thing about how to refill it. I down loaded a couple of PDF's with no luck finding the refill plug. Why is something a mower owner needs to know not in owners manual? I will probably have to change oil seals to stop leak if no other damage is found. Any help will be welcome. Thanks in advance---Cambre