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.

Sounds to me like your making good progress! Scraping the seats for the liners, Yes I remember doing that on the WD45 block. Don Bradley was coaching me over the phone on that build. He kept telling me that I needed to scrape the seat more, and he was correct. I kept getting material from that area. I think I ended up at .004. My block may not have been machined. I would think the machine shop would have bored the seats .005 deeper? Maybe this thread will get me motivated to work on my CA puller? Thanks!

Regards,

 Chris and Cheryl 

The journals on the crank are spot for .030 undersize at on 2.3443 - 2.3447 (AC service manual says 2.374 - 2.375 for STD).

The bearings are measuring 2.3515-2.3525 with the shim packs and bolts torqued to spec. The manual says .001-.003" clearance and I have more like .006-.007". I pulled one thin shim and it tightened things up just a tad but not much, so it looks like I will have to file down the edges of the bearing inserts slightly.

Anything I could be missing before I start removing material? The bores of the caps and backs of the inserts are clean. I'm suspecting the new bearing inserts are just a little tall/large.

Since the crank is dead nuts where it should be, I think either something is off with my rods/caps or the new aftermarket bearing inserts. Not sure what else I could be missing.

I do have another set of rods now that I think about it. It's probably worth cleaning those up and trying bearings in one or two to see where the ID comes out at.

I'm leaning towards ordering a set of Mahle/Clevite .030 rod bearings if I can find those, in hopes that the Reliance bearings are the issue.

I need to check the mains first in case I end up having to order another set of those too.

Good luck at the pull this weekend.

I ordered another set of Reliance .030 rod bearings again today. I reviewed more instructions on here and in the manuals about the bearing crush, and snugged up one cap bolt and then the second just past finger tight and measured the gap with feeler gauges. That was 0.010", which if split between the 2 sides would have been 0.005" crush. The spec is 0.0015".

I filed down the inserts roughly equally and got down to 0.0015" crush. Measuring in the same direction as piston travel gives me 0.002" clearance to the crank, but measuring perpendicularly (near but not on the parting lines/edges of bearing inserts) gives me 0.005-0.006". Spec clearance is 0.001-0.003", so not ideal, but it's at least not in the direction of the piston travel. Thoughts?