Pulleys Archives - UnderhoodService
Tensioner Tech Assist

The Lift and Pin is designed to simplify tensioner replacement and belt installation. This video is sponsored by Litens.

What To Inspect Before Replacing The Serpentine Belt (VIDEO)

Friction between the belt and pulleys wears away at the belt. This video is sponsored by the Group Training Academy.

VIDEO: Belt Tension And Friction Levels

Belt tension creates friction between the belt and the pulleys. This video is sponsored by Litens.

VIDEO: Belt Failure Due To Crankshaft Pulley

When the rings separate, the alignment of the belts change. This video is sponsored by Auto Value and Bumper to Bumper.

VIDEO: Are All OAD Pulleys The Same?

Andrew Markel explains why two overrunning decoupler pulleys (OAD) may look the same on the outside, but on the inside they may be different. The reason for this is that the OAD pulley is tuned for the engine, drive belt system and alternator. Sponsored by Litens.

VIDEO: What Is A Torsional Vibration In The Belt Drive And Pulley System?

Andrew Markel covers how the movement of the pistons create torsional vibrations in the belt drive system. These small changes in the speed of the crankshaft can cause vibration in the alternator and belt drive system. If the vibration goes unchecked, it could lead to belt wear and component failure. Sponsored by Litens.

VIDEO: Belt Plane Alignment

In this Maintenance Minute, Andrew Markel discusses how even 2mm can mean everything when it comes to belts. Sponsored by Dayco.

Tips for identifying timing belt, tensioner and idler failure

Courtesy of SKF When identifying timing belt, tensioner and idler failure, the first sign of wear is noise. For example, if the tensioner sounds bad, it’s usually bad. Start by listening to hear if any noise is coming from the timing cover or front assembly while the engine is running. Bad bearings make a high