Mainshaft Nuts

1 products

Our mainshaft nuts for Harley-Davidson — listed under Transmission — are the mainshaft retention nuts used on modern Harley-Davidson Big Twin transmissions. Iron Stable is run by Iron City Motorcycles, an authorised Harley-Davidson dealer in Leeds, and this small section is supplied by MCS. Typical fitment covers 1990–2026 Big Twin — spanning Evo, Twin Cam, and M8 Harley-Davidson platforms. Fresh mainshaft nuts are single-use items in most workshop manuals for any serious Harley-Davidson transmission rebuild. Browse the full range below.