Adapting to Change

Adapting to Change

Dayco explains how its aftermarket solutions are driven by tightening legislation and the pressure applied to vehicle manufacturers.

One of the most powerful drivers of change is governmental legislation, and in few areas is that more evident than in the automotive industry, where legislation influences everything from lighting to safety standards in the event of a collision.

Understandably, activities that have an effect on the environment are particularly highly regulated, which is why one of the key areas that appears to be under almost continuous review is the level of exhaust emissions emitted by the internal combustion engines (ICE) that are still used to power the majority of the world’s vehicles.

In order to minimise the environmental impact, vehicle manufacturers (VMs) work alongside their manufacturing partners to design and integrate solutions that reduce the level of emissions their ICEs produce, as well as the amount of fuel they use.

These design solutions naturally filter through to the aftermarket, and as a demonstration of how the market is shifting to include new products developed to tackle the technical challenges of ever-changing engine design, Dayco has introduced several new references into its aftermarket programme, including the auxiliary belt tensioner and water pump friction wheel drive for the PRINCE BMW PSA engine, utilised in many common vehicle models, such as Mini Cooper S, BMW 1-3 series, Citroen C3-C4, PSA 208-3008.

One of the most interesting characteristics of this power plant is the system that controls the water pump, which is activated only when the temperature of the engine needs to be controlled. Dayco designed, developed and manufactures for OE fitment both the single- arm torsion bar tensioner, which replaces the traditional spiral spring tensioner on the auxiliary drive system, and the motorised ‘switchable’ friction pulley that actuates the water pump.At start-up, or whenever the engine is operating below its optimal temperature, the water pump is disengaged, which decreases the engine’s warm up time, reduces its overall emissions and improves fuel consumption. However, once the engine reaches a predetermined temperature, the friction wheel is activated, and the water pump engaged, therefore allowing the engine to optimise its thermal management.

To prevent excessive acceleration forces on the bearing during off/on operations, the friction wheel is in constant contact with the back of the auxiliary belt that runs around the crankshaft pulley. With the use of an electric motor and small planetary reducer, which works in conjunction with a multi-function control system, the pulley’s radial movement is altered, and the rotating friction wheel comes into contact with the surface of the water pump pulley, and thus the water pump is brought into operation.

Due to the confined space around these components, a traditional auxiliary belt tensioner could not be employed, which therefore required Dayco to design another solution, this time in the form of the single- arm torsion bar tensioner for the auxiliary drive system.

Technicians in particular need to be aware of this development because it is a very different solution to the traditional design they are generally familiar with and without prior knowledge, it could potentially lead to the misdiagnosis of faults or an ineffective repair. However, being made aware of the differences in the system, they will be able to make their diagnosis with this in mind and accordingly implement the correct repair.

The friction wheel, belt and tensioner, along with the water pump and its pulley, are all now part of Dayco’s aftermarket programme, which affords independent workshops the ability to offer their customers a like-for-like replacement that provides them with an alternative to the franchised dealer. Naturally, Dayco also offers the replacement auxiliary belt, plus a wide range of parts and kits for this popular engine.

For more information regarding the power transmission products in the Dayco range, click here. visit

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