31-2039 Shaft idler gear

Maintaining the timing chest on a vintage Big Twin requires parts that match the original geometry perfectly. This S&S shaft idler gear is a high-quality, stock-style replacement for OEM 25791-36. It is designed to fit 1936 to 1969 Big Twin models, covering everything from the early Knuckleheads through the Panhead era and into the early Shovelheads. S&S parts are known for their durability and precision, making this idler gear an excellent choice for restorers and mechanics who want to ensure their vintage drivetrain remains reliable. It provides the smooth gear mesh and quiet operation essential for a well-tuned classic Harley-Davidson engine.