{"product_id":"motorshop-big-twin-4-speed-transmission-mainshaft-assembly-part-17-0653","title":"Motorshop Big Twin 4-Speed Transmission Mainshaft Assembly – Part 17-0653","description":"Big Twin mainshaft assembly.\n\u003cp\u003eThe Motorshop Big Twin Mainshaft Assembly, Part 17-0653, is a complete 4-speed transmission mainshaft kit designed for select 1970–1979 Harley-Davidson FL models. This assembled replacement unit helps simplify transmission service by combining the mainshaft and related bearing, gear, retaining, thrust washer, nut, lock tab, and bearing housing components into one coordinated assembly. It is suited for restoration, drivetrain repair, and replacement applications where dependable fit and proper component compatibility are essential.\u003cbr\u003eFeature: Complete assembly includes a 12-1\/2-inch 4-speed transmission mainshaft, mainshaft bearing lock tab, 4-speed transmission bearing housing, main bearing, transmission mainshaft bearing nut, mainshaft 1st–2nd cluster gear, stock 24-tooth 3rd gear mainshaft, 3rd gear retaining ring, and a .063-inch 3rd gear thrust washer. The unit is supplied assembled to help reduce installation time and simplify parts selection during transmission rebuilding.\u003cbr\u003eFeature: Designed for compatibility with 1970, 1971, 1972, 1973, 1974, 1975, 1976, 1977, 1978, and 1979 Harley-Davidson FL applications. Always compare the original transmission configuration and component specifications before installation to confirm application compatibility. Motorshop Part 17-0653 is manufactured in Taiwan.\u003cbr\u003eAccessory Items: 17-0142 - 12-1\/2 inch 4 Speed Transmission Mainshaft, 17-0668 - 12-1\/2 inch 4-Speed Transmission Mainshaft Kit, 17-8502 - 12.470 inch 4-Speed Transmission Mainshaft, 16-0680 - Jims Primary Locking Bar Tool. Suggested related components include 17-0141 - 12-1\/2 inch 4-Speed Transmission Mainshaft, 12-1103 - Transmission Mainshaft Bearing Nut, 17-9774 - Bearing Housing Right Side, and 12-0307 - Transmission Main Ball Bearing.\u003c\/p\u003e\u003cp\u003e\u003cb\u003eFeatures:\u003c\/b\u003e\u003c\/p\u003e\u003cul\u003e\u003cli\u003eBrand: Motorshop\u003c\/li\u003e\u003c\/ul\u003e\u003cul\u003e\u003cli\u003ePart Number: 17-0653\u003c\/li\u003e\u003c\/ul\u003e\u003cul\u003e\u003cli\u003eProduct Type: Big Twin 4-speed transmission mainshaft assembly\u003c\/li\u003e\u003c\/ul\u003e\u003cul\u003e\u003cli\u003eMainshaft: 12-1\/2-inch transmission mainshaft\u003c\/li\u003e\u003c\/ul\u003e\u003cul\u003e\u003cli\u003eGear Configuration: 1st–2nd cluster gear with stock 24-tooth 3rd gear mainshaft\u003c\/li\u003e\u003c\/ul\u003e\u003cul\u003e\u003cli\u003eIncluded Components: Bearing lock tab, bearing housing, main bearing, bearing nut, retaining ring, and .063-inch 3rd gear thrust washer\u003c\/li\u003e\u003c\/ul\u003e\u003cul\u003e\u003cli\u003eApplication: 1970–1979 Harley-Davidson FL models\u003c\/li\u003e\u003c\/ul\u003e\u003cul\u003e\u003cli\u003eUOM: KIT\u003c\/li\u003e\u003c\/ul\u003e\u003cul\u003e\u003cli\u003eCountry of Origin: Taiwan\u003c\/li\u003e\u003c\/ul\u003e\u003cul\u003e\u003cli\u003eAccessory Items: 17-0142 - 12-1\/2 inch 4 Speed Transmission Mainshaft, 17-0668 - 12-1\/2 inch 4-Speed Transmission Mainshaft Kit, 17-8502 - 12.470 inch 4-Speed Transmission Mainshaft, 16-0680 - Jims Primary Locking Bar Tool\u003c\/li\u003e\u003c\/ul\u003e\u003cbr\u003e\nFitment\u003cbr\u003e\nHarley Davidson FL  1970\u003cbr\u003e\nHarley Davidson FL  1971\u003cbr\u003e\nHarley Davidson FL  1972\u003cbr\u003e\nHarley Davidson FL  1973\u003cbr\u003e\nHarley Davidson FL  1974\u003cbr\u003e\nHarley Davidson FL  1975\u003cbr\u003e\nHarley Davidson FL  1976\u003cbr\u003e\nHarley Davidson FL  1977\u003cbr\u003e\nHarley Davidson FL  1978\u003cbr\u003e\nHarley Davidson FL  1979\u003cbr\u003e\nHarley Davidson FL  1980\u003cbr\u003e\nHarley Davidson FL  1981\u003cbr\u003e\nHarley Davidson FL  1982\u003cbr\u003e\nHarley Davidson FL  1983\u003cbr\u003e\nHarley Davidson FL  1984\u003cbr\u003e\nHarley Davidson FL  1985","brand":"Motorshop","offers":[{"title":"Default Title","offer_id":67747146760377,"sku":"17-0653","price":354.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0692\/2285\/8794\/files\/17-0653a.jpg?v=1792186607","url":"https:\/\/atticusgoods.com\/products\/motorshop-big-twin-4-speed-transmission-mainshaft-assembly-part-17-0653","provider":"Atticus Goods","version":"1.0","type":"link"}