A complete repair kit suitable for is sold here Tuff Torq gearbox K51A John Deere AM880202 K51D Simplicity 1720108SM K51E John Deere AM129821 If you are not sure whether this set fits your gearbox, just write an email. If you have problems identifying your transmission, I would be happy to help you. I'll check it and tell you afterwards Notice. More Tuff Torq Spare parts on request.
