Dayco is urging workshops to ensure they fit all additional components it supplies with its belts, tensioners and idlers.

Among these additional items are crankshaft pulley bolts, which when specified for replacement is usually because they are stretch bolts and therefore, for safety reasons, must not be reused.

To provide the greatest level of transparency, Dayco distinguishes these kits with the letter ‘K’ at the end of the part number.

Dayco national sales manager, Steve Carolan said: “In order for them to complete a full and thorough repair, it is vital that technicians replace all the components and ancillary items such as nuts, bolts, studs and circlips that the manufacturer has stipulated must be changed at the designated service interval.

“Although without access to the manufacturer’s service and repair information, it is sometimes difficult for technicians to find the precise details of which additional items this requirement applies to, we have made things considerably easier for them by including all the items that need to be replaced in the kit.

“So, the message is: ‘If it’s in the box, it must be changed’.

“An example of how this practice benefits workshops can be seen by looking at some popular applications, all of which contain additional parts, but for some of these the manufacturer also stipulates changing the crankshaft bolt, designated with the ‘K’ at the end of our part number, whereas others do not.”

Taking the the Focus 1.6-litre petrol from 2011 to 2015 as an example, Ford specifies that the crankshaft bolt is changed during a scheduled timing belt replacement, (Dayco kit KTB764K), a step not required for the Vauxhall Insignia 2.0-litre diesel from 2009 to 2017 (KTB847).

It’s a similar story with Dayco’s combined timing belt and water pump kits as the 1.6 diesel in the Citroën C4 Picasso from 2006 to 2013 also requires a new crankshaft bolt (KTBWP9140K), whereas the 1.9 diesel in the VW Golf from 2003 to 2009 (KTBWP2964) does not.

Dayco is the OE timing belt supplier for each of these examples, and three of the four engines utilise its unique high tenacity (HT) or ‘white’ belt.

“Therefore to provide their customers with a genuine like-for-like replacement, workshops need to ensure their technicians fit a Dayco kit, because only Dayco manufactures the HT belt,” Steve added.