Lisle idler pulley plug and gasket kit, 5-piece oversize thread repair — fits 13–19mm, 3/8" & 1/2" drives

Lisle 58650 is a five-piece plug and gasket repair kit designed to restore damaged idler pulley threads by cutting a controlled oversize thread for a reliable seal.

This compact kit contains the plugs and gaskets needed to replace worn or stripped threads on idler pulleys and similar fittings. Rather than replacing the entire pulley assembly, the Lisle 58650 lets you re-establish a perpendicular, leak-resistant thread so fasteners and gaskets seat correctly. It’s made to pair with Lisle’s tapping tool (see model 58850) and matches common hex and square drive requirements found on many service pulleys.

How does this set repair damaged threads without replacing the pulley?

The kit supplies oversize plugs and matching gaskets that let you tap a new thread where the original is stripped. When used with the proper tapping tool the new thread is cut perpendicular to the gasket surface, restoring proper engagement and sealing. This approach saves time and cost versus changing the pulley.

• Includes five plug-and-gasket combinations sized for common idler applications.
• Works with Lisle tapping tool 58850 to ensure correct thread alignment.
• Re-establishes mechanical engagement and compresses gaskets for tight seals.

Which fastener sizes and drives does the Lisle 58650 accommodate?

The plugs are intended for idler pulleys that accept a variety of hex sizes and square drives. The kit fits hex sizes that cover the most frequently encountered pulley hardware, plus options for both 3/8" and 1/2" square drives. That range makes it versatile for domestic and many light-commercial vehicles.

• Compatible hex sizes: 13mm, 14mm, 15mm, 16mm, 18mm, 19mm.
• Supports both 3/8" and 1/2" square drive configurations.
• Designed to pair with Lisle tool 58850 for thread cutting accuracy.

What makes the tapping action leak-resistant on rethreaded pulleys?

The kit’s design ensures the tapped oversize thread is perpendicular to the gasket surface so the gasket seals evenly around the fastener. Proper perpendicularity prevents gaps and reduces the chance of fluid seepage. Using the recommended Lisle tapping tool helps maintain that precise angle during thread cutting.

• Unique tapping geometry aligns the new thread with the gasket face.
• Even gasket compression reduces uneven wear and leakage paths.
• Replacement parts are matched to Lisle 58850 for consistent results.

Who is this kit intended for? Technicians, home mechanics, and fleet maintenance personnel who regularly service belt systems and idler pulleys will benefit most. If you encounter stripped pulley threads or want a cost-effective repair option that preserves original components, the Lisle 58650 provides the plugs, gaskets, and compatibility needed to restore secure fastener engagement and reliable sealing when used with the correct tapping tool.