I have a 4212, but it isn't helping me with the crank pulley. I asked a John Deere mechanic at a Kenworth/JD dealer and he said to use the crank pulley, then check that the #1 valves are closed when on the mark. The pulley has the marks I mentioned, but I'm not seeing anything about it in the 4212. The 4212 doesn't cover my injection pump either. The version of the 4212 for my tractor, doesn't seem to be available. The dealer parts guys couldn't find the info either. Why did JD put marks on the pulley with a place on the housing to line up with, if it isn't used? The info in the manual about the pin isn't detailed well either. The dealer could't find any detailed info in the parts manuals either. They could only guess what I had, that is why he said to use the pulley marks. I thought the marks would be more obvious in their meaning. I was there an hour.