Next time you utilize a drive belt, timing belt, or timing chain, you’ll likely need to loosen a tensioner pulley to eliminate it. Following these general suggestions and specific guidelines from your own owners manual or repair manual, your belt or chain will function for the life span of your car.
Toyota and various other timing belt tensioners are loosened by simply removing them from the engine. You need to gradually compress them in a bench vice and lock them with a pull-pin before reinstallation.
Hydraulic (not hydraulic-damped) tensioners are nearly always situated in the timing case, mostly upon automobiles with timing chains, while some are used in combination with timing belts. Hydraulic tensioners are powered by essential oil pressure from the engine oil pump and could press on a tensioner pulley (timing belts) or pressure slipper (timing chain). You’ll likely need the entire year, make, and model details, and you may have to use special equipment for this sort of tensioner pulley.
Typically, a hydraulic tensioner needs to be “reset” and locked after removing it from the engine. Remove the lock only following the tensioner, pulley, or slipper, and timing belt or timing chain are installed and aligned.
The Car Pulley Belt Spring maintains tension, as the hydraulic damper keeps it from bouncing under load changes. This prevents timing belts and timing chains slapping and jumping teeth and helps to keep drive belts from slipping and making sound. To loosen a drive belt spring tensioner pulley, refer first to the restoration manual or owners manual’s specific calendar year, make, and model information.
You might need a special tool, but many spring tensioners have a square hole, for a 3/8” or 1/2” breaker bar, or a hex or square protrusion for a wrench or socket. Using the correct tool, release tension on the belt. You’ll need to hold some springtime tensioners while slipping on a new belt. Others may possess a locking mechanism, like a hole for a locking pin or hex key.
To loosen an NAI tensioner, loosen the locking nut or bolt, then back off the tensioner screw. Force the pulley toward the other pulleys or components, loosening the belt.
Spring tensioner pulleys, because the name implies, use a spring to hold tension on the belt. Most, if not absolutely all, springtime tensioner pulleys are NAI tensioners you need to include a hydraulic damper. They are more technical and costly but don’t require adjustments and are less susceptible to user error.