Manual Transmission Parts for Hummer H1 | eBay www››Car & Truck Manual Transmission PartsManual Transmission Parts for Hummer H1; Skip to page navigation. Filter. Manual Transmission Parts for Hummer H1. Do these parts fit your vehicle? Find out now. Enter vehicle info. Tell us about your vehicle to find the right parts faster + Hot This Week. National Oil Seals 710928 Input Shaft Seal. Autotrader Find: Manual Transmission Hummer H3T Off-Roader Although most off-roaders primarily find the "original" Hummer H1 to be the most appealing Hummer model, there's another Hummer that's enticing to enthusiasts: A manual transmission version of the H3T pickup, which is one of the rarest General Motors pickup truck models built in recent years.