Hello Tom. First, thanks for your concern about my credibility. Lord knows it could use some shoring up. This issue however about the coupling is a very real matter. I have been servicing Mark VII machines for some time, maybe 16 years. I have tried to buy the coupling many times, the last about 12 months ago. Because the local distributor in south FL is sooo incompetent, and the fact that I keep several of your machines alive, I can buy parts direct from the factory. I was told on several occasions that I could not buy the coupling only. Had to buy the whole pump. This aparantly happened to IBFLYING, who started this post. Contrary to popular belief, some of us that post things here do not sit awake all night and make these things up to annoy people. These are the real world experiences that are reported. So it seems that some distributors and the factory are misinformed as how to sell the coupling. If you could inform parts sales, you will make life easier and cheaper for many operators. And if Oberdorfer is not a German manufacturer, as I mentioned, what are they? Yiddish? Spanish? Just sound German to me. Also the fact that you pay way more than 20 bucks for this is part of the problem of replacement parts cost. Go to any large power transmission shop in your area, and simply look at what is available for many applications similar to this. Look in the Grainger catalog. Twenty bucks is about right.