Belt Tensioners

Does the belt squeal on a cold start, or is it time to replace the timing belt on your project? A belt tensioner keeps the correct tension so the drive belt doesn't slip and the timing belt doesn't jump teeth. We have tensioners for both timing belts and drive belts for you who service or rebuild your engine.

What does a belt tensioner do?

A tensioner presses a pulley against the belt and keeps the tension within a specific range while the engine warms up and the belt wears. Tensioners for timing belts control the belt that synchronises the camshaft and crankshaft. Tensioners for drive belts maintain tension on the belt that drives e.g. the alternator and water pump. Some tensioners are automatic with a spring or damper, others are adjusted manually. A worn tensioner can cause squealing, a vibrating belt or uneven wear, and on a timing belt a failure can, depending on the engine, lead to engine damage.

How to choose the right tensioner

• Engine and year: Tensioners are typically specific to the engine. The Gates tensioners here are listed by model and year, e.g. Toyota Supra 93-98, Lexus IS300 and Mitsubishi Eclipse with 4G63 Turbo.
• Belt type: Timing belt and drive belt tensioners are not interchangeable.
• Automatic or manual: It depends on what the engine is designed for.
• Related parts: Pulleys and belt wear at the same rate. A timing belt kit often combines belt, tensioner and pulleys.

Installation and maintenance

The tensioner is typically replaced together with the belt, because the bearing and spring wear along with it. Follow the engine's specifications for tension and tightening torques. Turn the engine over by hand after installation and check that the marks still line up. If you hear bearing noise, or the tensioner arm moves erratically at idle, the tensioner should be checked.

Frequently asked questions

Should the tensioner be replaced together with the timing belt?

It is typically recommended, because the bearing and spring or damper wear along with the belt. An old tensioner on a new belt can give incorrect tension and shorten the belt's service life. Follow the service interval for the specific engine.

How can I hear or see that a belt tensioner is worn?

Typical signs are squealing or squeaking, rumbling bearing noise, a tensioner arm that vibrates at idle, or uneven wear on the belt's edge. The noise can also come from the belt or a pulley, so check the parts one by one.

Can I use a drive belt tensioner on the timing belt?

No. Timing belt and drive belt tensioners are designed for different belts, loads and positions. Choose the tensioner based on engine, year and belt type, and compare the part number with the original part or the engine's documentation.