Humming, clunking, and whining are noises you would rather hear from younger passengers than from your STi transmission. Unfortunately, today is not your lucky day. Fortunately, you can find a generous selection of new and used transmissions for your Subaru in the large inventory on eBay. Outfit your 2007 Subaru Legacy with a six-speed automatic transmission or equip your 2010 Outback with a cable-shift manual transmission unit. Shop for OEM parts for that new car feeling or opt for a used or rebuilt transmission to save a little money. If you want to rework what you have, purchase a rebuild kit instead and spend time puzzling in your garage. Alternatively, send your existing transmission and the rebuild kit to a local mechanic. Choose one of several type of STi transmission swaps and convert your automatic transmission to a manual, or vice versa. Before you get started on your project, pick up a set of STi transmission mounts and other essential components. Select the right STi transmission type for your Subaru to roll smoothly off into the sunset.