Jims Tools Big Axle Powerglide Hydraulic Tappets

Jims Big Axle Powerglide hydraulic tappets (also called hydraulic lifters or valve lifters) are American-made replacement tappets for Harley-Davidson V-twin engines. They use a simplified roller design that removes the inner bearing race, so the tappet is more stable and durable than the stock design.

Key Features:

• Big Axle design: The axle is about 36% larger. It also serves as the inner race, so the pin bearing and roller assembly turn directly on the axle. This removes movement in and around the axle.
• Thicker roller wall: The outer roller wall is about 27% thicker. This reduces distortion and helps the roller track the cam lobe more accurately.
• Smaller pin bearings: Pin bearings are about 12% smaller, which supports higher RPM and more precise cam tracking.
• Stronger and more stable: Jims describes the result as a tappet with roughly twice the strength and stability of the stock design.
• Made in the USA: The hydraulic unit cavity is hand-honed.

These tappets suit engine rebuilds and performance builds where valvetrain reliability matters. Each part number is sold individually. For best results, install and adjust the tappets following the Jims instruction sheet for your part number.