920101 Monster OAD

An Overrunning Alternator Decoupler or OAD has been used in the automotive industry for twenty years. But the Monster OAD™ Decoupler Pulley (keyed and splined), by Litens is new.

Designed specifically for buses and a first for the transit industry, this part reduces the number of unexpected bus breakdowns caused by premature engine failure. This component also addresses issues with expensive maintenance.

Here’s How It Works – Torsional Vibration The Monster OAD™ Decoupler Pulley eliminates the effects of torsional vibration. Torsional vibration is a term used to describe the firing pulses that happen each time a cylinder fires and causes the crankshaft to speed up or slow down.

These firing pulses act on the alternator rotor, affecting its speed during every revolution of the engine. These pulses create vibrations for the drive belt and cause the belt tensioner to exhibit increased movement.

The more tensioner movement, the less durable the tensioner, the belt, as well as all the components within the belt drive system including the alternator, become. The Monster OAD™ Decoupler Pulley reduces the tensioner movement and increases the durability of these important parts.

Torsional vibration can cause serious side effects to your vehicles front-end accessory drive, including:

• High dynamic belt tension fluctuation
• Higher tensioner motion and wear
• Increased in-vehicle vibration or rumble
• Noise during start, stop or gear shifting
• Steering wheel shudder
• Reduced belt and bearing life
• Belt flipping
• Belt derailment or belt loss
• Premature wear of all the vehicles accessory drive components.
• The Litens Monster OAD™ has a patented torsion spring which acts as a suspension system for the alternator. It absorbs the torsional vibration which has a serious impact on the durability of the vehicle’s drive system.

Another important function to the Litens OAD™ is the overrun function, which allows the alternator to slowly stop when the vehicle’s engine shuts off.

A slow, gentle stop eliminates the shutdown noises, (that sound like a chirp), that are created when the alternator rotor’s mass over-spins as the vehicle shuts down.

The overrun function also works during transmission shifting, when the alternator’s rotor spins faster as the engine decelerates.

One Part with Huge Benefits
The Monster OAD™ Decoupler Pulley is quick and easy to install and provides significant benefits for bus operators and the transit industry, including:

• Reducing roadside service calls due to the failure of any of the Front-End Accessory Drive’s (FEAD) system components
• Reducing fuel consumption and thereby increasing mileage
• Reducing overall FEAD system maintenance
• Extending the bearing life for all components of the FEAD system
• Eliminating shut down belt squeal and wear
• Eliminating belt hop between first and second gear shifts
• Reducing or eliminating belt breaks
• Tripling a belt’s lifespan
• Reducing belt temperatures by 20%
• Doubling the life of the belt tensioners

It’s no wonder that Cummins North America has approved the Monster OAD™ and is recommending it on all new bus production as of November 2018.

This part has been field -tested and accepted by large-scale metro transits in North America. This includes aftermarket installations and New Flyer Industries, which have been offering the Monster OAD™ on their products.