1951 WD

They did point out some tiny cracks around one of the 3/8" stud holes for the cylinder head. It looks like there's still a broken off piece of stud way down in the bottom of it so I'll carefully set this up in the drill press and take care of that. The shop wasn't concerned about the cracks and I'm not really either, but I may get a pic of it later this week. No cracks in between the cylinders anywhere.

I'm crashing onwards with the pump. Everything is cleaned up and I picked up most of the parts I needed. Just waiting on a few that my dealer didn't have in stock.

I ended up doing some light filing plus Scotch-brite work to clean up the worst scores in the bore, and some damage to the rearmost control valve sleeve. I noticed two small mangled pieces of metal in the parts washer today that probably caused the damage. I'm not sure where they were hiding at, but that's why it's always good to thoroughly clean everything, right? Files in control valve bores like this is a huge no-no but I figured I didn't have anything to lose on this pump. We'll see if it works out.

There were 7 shims on the unloading valve. I decided to leave all of them in. I need to get a 5000 psi gauge so I can check pressure once I have the tractor back together.

The AC service manual says you should replace the unloading valve as an assembly. However they are no longer available in 2024. They also provide a procedure "for emergencies" for reusing an old unloading valve with a new ball. You are supposed to press the ball into the seat with 5000 pounds of force and then clean up any deformation in the hole afterwards. I pressed gently with a 20 ton hydraulic press - maybe I only actually got 1 or 2000 lbs. of force on it, but I didn't want to overdo it since I don't have a pressure gauge on my press.

I am hoping someone can help me with this linkage from the drawbar - anybody have one loose laying around their shop that can take a measurement of where the hole for the crosspin should be located?

The shaft came loose from the external arm at some point in the tractor's life and they (poorly) welded it back on, and the welds broke. I have the shaft out, cleaned up, and ready to weld back in but I don't want to mess up the hole orientation. The way the crosspin holds the internal linkage to the shaft seems like it would be important. The first pic shows how it was when I removed it, and I suspect that is not correct.

EDIT: Second pic shows the shaft backwards. Luckily it is not welded yet, ha.

70224506 would be the PN of the regulating shaft assembly, in case you have one loose and can show how the hole in the shaft is oriented relative to the plate it is pressed into. Otherwise I might be SWAGing it based off of what I can see in the parts book diagram... which is not very scientific.