

We have to have our trucks emissions tested every year. This January the shop that did the testing and certification for us replaced the perfectly good and high quality Donaldson Power Core filter (the filter restriction gauge was showing zero restriction) with a cheap no name filter element. They probably buy them for twenty bucks and sell them for eighty bucks and install them, whether the trucks need them or not. Easy way to make sixty bucks. That filter element is widely used on Medium Duty trucks.
Well, they will not be able to pull that scam any more on us. I took off the M6 screws and drilled and tapped for 1/4 in C tamper resistant screws (snake eyes type). I even wrote "do not replace filter" on the filter housing, not that it is going to stop them from replacing the element. The tamper resistant screws will stop them.
As an aside, someone tried to steal the three batteries from this truck. Replacement cost for the three batteries would have been close to six hundred dollars. They disconnected the battery cables and that is when they noticed the tamper resistant nuts (TuffNuts) I had used on the battery holddowns and they gave up.
Subject truck is a 2004 Freightliner M2 Business Class with a Mercedes 906 engine. Superb engine, BTW.