The Real Deal From INA

INA, the inventor of the overrunning alternator pulley (OAP), stresses the benefits of investing in genuine parts to protect the vehicle’s front end accessory drive (FEAD) system.

As a development partner and OE supplier to virtually every vehicle manufacturer around the globe, INA is at the forefront of modern engine technology. INA’s engineering team developed the hugely successful overrunning alternator pulley (OAP) to help the front end accessory drive (FEAD) system cope with ever-increasing demands from larger, more powerful alternators.

The alternator has the biggest impact on the FEAD system and the OAP counters this by allowing the alternator to decouple from the drive system, thus preventing premature wear and helping the engine run smoothly. With an aftermarket range of over 160 part numbers available through FPS, INA offers a portfolio to rely on for genuine OE OAP units.

In a bid to reduce CO2 emissions and comply with the demands of EU legislation, smaller, lighter and more powerful turbocharged three-cylinder engines have been developed. These engines are built with higher output alternators that handle all the electrical gadgets that are considered as standard equipment on a modern car.

With fewer cylinders and engines without a balancer shaft as seen in modern vehicles, the combustion cycle becomes more volatile and the FEAD system has to compensate and work harder to quell the higher vibration values. It is therefore critical that the OAP and FEAD systems are checked regularly for wear, correct operation and noise, all of which are tell-tale signs that the FEAD system needs maintaining.

The 1.0L engine in a Daihatsu Charade (1988-92) generated just 53bhp and needed an agonising 15sec to propel the 2,000lb hatchback to 60mph, albeit with a reasonable 38mpg highway fuel economy rating.

The Ford Fiesta (2014) also has a three-cylinder 1.0L engine, but produces 123bhp, has a 45mpg highway fuel economy and gets to 60mph in 8sec, while weighing 800lb more than the Charade!

Failure of a worn OAP is commonly misdiagnosed as tensioner failure due to excessive belt slap. But the tensioner breaks only when it operates way outside its normal tolerances.

Changing the tensioner alone will only treat the symptom and not the cause, leading to repeat failure. The issue could instead be with a worn OAP that is no longer allowing the alternator to overrun, protecting the FEAD system from vibrations and premature wear.

The OAP can be identified by its distinctive black protection cap and requires the use of a special tool to ensure a professional removal and replacement.

A genuine INA OAP continues to maintain its full running properties even in the unlikely event of a failure as it is engineered to fail in a ‘locked’ position. This allows the auxiliary belt to continue driving the alternator even when the internal mechanism of the OAP has failed.

Since no other brand includes this critical feature, there will be no drive to the alternator when it fails. It is therefore wise to always go for a genuine INA part, as it guarantees against emergency breakdowns.



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