Interesting difference in timing belt tensioner

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Just an observation that my 2.8 TD timing belt tensioner does not have a 3/8" square hole, as the tech manual says, to put the torque wrench in but a 5/16" hex.

Many aftermarket

Many aftermarket manufacturers do this to save money. 5/16th punches and dies are cheaper to buy, and it uses less power to make them. Multiply this by the millions they manufacture and it adds up to a fortune saved in manufacturing costs, and more profit.