Semi Truck PCV Valve Diaphragms

Traced the screaming noise in the engine to the PCV valve, and a torn diaphragm. Most places suggest replacing the whole oil separator cover, but Dorman now offers this kit consisting of a new diaphragm and a new cover, to replace the one that is inevitably destroyed when you do the job. Note the position of the 'groove' in the top of the old cover. Use a chisel or screwdriver to break the bottoms off the six 'slots' in the old cover. Lift it off and toss it. Clean up the area and, having made sure the new diaphragm is correctly located in the new cover, place it gently over the PCV 'tower', keeping the 'groove' in the right place, and the slots over the pegs in the tower. Push the cover down so that the slots pop over the pegs and lock down. This is tricky, and I found I needed to go around each slot and tap it down with a hammer and an extension rod. If you don't get it down tight all around, you'll get a sighing/groaning noise at idle and shut-down. Nice solution costing much less than a new oil separator cover, and taking less than 10 minutes.