MIGHTY AUTOMATIC MIGHTY AUTOMATIC BELT TENSIONERS

Belt Wear, Check The Tensioner Automatic belt tensioners are designed to keep the belt tight on the pulleys. Often, these tensioners have a built-in belt wear indicator. Just like an oil dipstick tells you about the oil level, the tensioner indicator will tell you about belt wear. It only takes a few minutes, and it’s an important part of routine maintenance

What To Look For …. Properly reading the tensioner’s indicator can tell you when the belt is in good shape or needs to be replaced Tensioners vary and have different styles of belt wear indicators, including raised lines, recessed bars or pointers Find out which indicator style is on your tensioner and learn how to read it. The preceding tensioner indicator example is a raised line. If the tensioner indicator points toward the belt being loose, the belt may be worn or stretched and must be replaced. If the indicator points toward the belt being too tight, an incorrect belt may be installed or an accessory may have an incorrectly sized pulley.

What To Do…. If the tensioner indicator shows signs of belt wear due to stretching, check the belt’s condition. If the indicator shows that the belt is too tight, make sure the correct belt is installed and all accessory pulleys are the correct size. If the belt shows signs of wear and potential failure, replace the belt immediately (see examples of belt wear on following slide) Always check the belt tensioner operation when replacing the belt. If the tensioner feels seized, is sticking or broken, or the pulley feels rough when you spin it, replace the tensioner immediately If you are checking one belt drive component, check them all. You will save your customers time, money and most importantly, an unexpected breakdown

Belt Failure Warning Signs

Tensioner Inspection Look, Listen, Feel LOOK: When inspecting a belt tensioner you must look at it while the engine is running as well as with the engine stopped. Below is a list of things to look for. They are warning signs that the tensioner may be worn out and that it may be time to replace it before you get stranded. Engine running at idle:  Look for excessive tensioner movement  Look for pulley wobble  Look for belt misalignment on the pulley Engine shut off:  Look at the pulley, is the belt running near the center?  Does the tensioner appear to be tilted off to one side?  Look for excessive corrosion on the pulley  Look for red rust colored dust coming out of the from of the tensioner  Look for damaged bearing seal or grease leaking out of the pulley bearing

MIDDLE TRACKINGSIDE TRACKING RUSTED PULLEY Proper Alignment - OK Worn Pivot Bearing-Replace Polish/Clean Surface What To Look For …. Click or Rattle Tilted

Tensioner Inspection Look, Listen, Feel LISTEN: With the engine running: Listen for any abnormal noises (belt squeaks, buzz or whining noises) coming from the belt drive. These noises often will increase when the engine RPM is increased, A/C compressor engages or power steering load increases. With the engine stopped: Remove the belt and spin the tensioner pulley by hand and listen carefully for any noises. This is a great time to inspect and rotate all of the pulleys in the belt drive system. Idlers, water pump, power steering, air conditioning and alternator should all spin freely without noise.

Tensioner Inspection Look, Listen, Feel FEEL: With the engine shut off and the serpentine belt removed: Use the correct tool to rotate the tensioner throughout its entire range. If the tensioner does not feel smooth, feels seized or is notchy, then it may need to be replaced. Feel the pulley with a gentle up and down rocking motion. If excessive play is noted, the pulley may need to be replaced.

Tensioner Damping We all know one job of the belt tensioner is to keep tension on the belt so it won’t slip. But the other job is to compensate for engine vibrations. This function is known as damping. The tensioner damping reduces vibration inputs through the belt the same way a shock absorber works with the suspension in your car to reduce vibration inputs from the road. Types of Damping: Friction Damping Can be external (visible) or internal (hidden within the part) Incorporates some type of nylon element that helps grip the internal components of the tensioner. Hydraulic Damping Easy to spot because there will typically be a small hydraulic shock absorber attached to the outside of the tensioner.

Tensioner Damping Hydraulic Damping Mighty Internal Damping

Tensioner Damping OEMMighty Damping Removed

Tensioner Damping What To Look For: The damping part of the tensioner can wear out over time. These worn-out systems don’t provide sufficient control of vibrations and might cause the tensioner to display excessive motion, permature wear-out and belts jumping off pulleys. The following are steps to spotting a potentially worn-out damping sytstem. Take note of how the tensioner damping feels when you cycle a tensioner to remove the belt. If it cycles very easily, then the damping element may be worn out. If the tensioner moves back and forth quickly, then the tensioner may require replacement. The center of the tensioner’s pulley should never move more than ¼”. The Mighty tensioners provide OEM quality in look, performance and installation because the majority of the Mighty tensioners are manufactured by the OEM source.