47 A no oil pressure

Finally got it running but not registering any oil pressure. This may be a little long but I want to give the story to this point in case anything may be relevant. Bought it in Feb-March SW Michigan, it wouldn't start but seller claimed he had it running last year. Got it home, carb was full of crud and corrosion, rebuilt it myself (bought the kit with new float and needle screws & drill bits), changed the oil and drained out at least 2 pints of water to start, then heavy sludge and slate gray oil. Decided to drop the pump to get a good cleaning and inspect the drive coupler, twisted off the smaller line that goes from pump to valve train, after locating a used line I began reassembly and had a washer drop out of the filter assembly area that had been above the filter, it was "cupped". I put it back in the way it appeared to have come out, "cup" towards the tractor and installed the filter. Now I got it started but had zero oil pressure so it ran maybe 30-45 seconds and I choked it to kill it. Some inquires about the washer in the filter assembly said that it appeared it had frozen and caused the washer to cup and this may cause a low pressure, anyone back this up? I didn't get this input until after I'd reassembled! What is the proper diagnosis procedure so as not to cause harm to the engine? I pulled the line running to the gauge and blew it out with air, it wasn't plugged. My own thought is to first drop the filter and flatten that washer out, but any input or advise would be greatly appreciated, it's been a long road but I have to admit I was thrilled to hear it run for the brief period it did!! Also when I tried to stall it to kill the engine I had no throttle "response", when moving the lever you can see that it is moving the linkage but there was no effect on the engine rpm's, it was chugging away at a steady pace until I choked it out? Thanks

You?re Tractor will run with no oil pressure even if there is no filter in there. With that being said, the only two things that I can think of that would cause no oil pressure is: is sheared off drive shaft coupling or a badly distorted filter housing created by over tightening the filter nut. The coupling is designed to shear if there is a problem with the oil pump such as water collected and frozen. It is fairly common or maybe not unheard of to say the least. It happened to me one time.

I bought a early 52 "A" that had been setting inside for 10 yrs. Took engine apart, removed pump & screen cleaned & decided to see if the oil pump was pumping & every thing was getting oil. I made a drive to spin flywheel with a big drill. I found left main brg. line rusted through, replaced with a good used line. After removing & checking the oil pressure regulator & the 2 gaskets I found a 3/16 hole rusted through the filter housing that is pressed into the crankcase. I got a used filter can. By putting hose clamps around the con rod journals letting a little oil squirt out I now have good oil pressure.

I dropped the oil filter out and there was no oil in the canister, so the pump isn't pumping at all. I straightened out the "cupped" washer that was above the filter that I mentioned in my original post and reinstalled. Took the crankcase cover off and watched the oil pump shaft as the flywheel was turned by hand and the shaft isn't turning. When I had the pump out the coupler looked fine, looked like the square of a 1/2 inch socket. Putting my phone in and filming the connection I can see it's fully seated where it's supposed to be. The camshaft gears look good. I'm wondering if the gear that drives the pump has been compromised? Is there a shear pin in it? How do I get in there to inspect? Any ideas? Thanks

I have seen the teeth on the drive gear that runs off the camshaft missing. no shear pin.

Do you know how to access the oil pump drive gear? Do I have to remove the governor cover or from the bottom side through the crankcase and remove the bearing assembly?