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I'm at my wit's end over this crankshaft pulley on my 1940 B.

I tried half inch bolts and althread in the crankshaft hole with no luck. I tried a half inch tap to chase the thread and it ate the end of my tap. I tried a 7/16 fine thread tap and it went in fine. I then tried 7/16 althread and it pulled out without getting started. I can't get a half inch fine thread bolt or althread even started into the hole. The threads are not boogered up and I'm officially stuck.

Yesterday afternoon I tried grade 5 half-inch course thread, both bolts and althread. No luck. This pulley has a hole for a set crew, but nothing in it. If I could find anything between 1/2" inch and 7/16" I would use that, but nobody has such a creature. I put it in the oven at 400 degrees for about an hour last night and it went on a little easier at first, then stopped with about 3/4" left to get it on completely; I used welding gloves rather than run the risk of my wife making me sleep in the barn with this tractor if I used her oven mitts on this thing.  I got it on the shaft and lined up with the woodruff key then my dad held a 2x6 block against the pulley and I hit it until I split two pieces of 2x6, and it finally stopped as I said before, with roughly 3/4" left to go.   I don't like the idea of hitting it and running the risk of messing up connecting rods or bearings.

I admit that I'm no machinist. I don't have any Farmall guys around me that I can call on for advice or even invite over to sit on a bucket and give my advice. Both of my grandfathers were pretty fair machinists, but they've both been gone for years and I have no brothers or cousins in the tractor mechanic business that I can call on for advice. It's just me trying to get this tractor running for our little girls who are expecting daddy to perform a miracle in the barn and make their pretty red tractor that they've been waiting for nearly a year on to be fixed.

I am open to any suggestions. And if anyone feels the need to publicly berate me as another member did on another tractor site by telling me that I didn't know what I was doing, that I better just quit, and that I needed to take it to someone who knew what they were doing, then I guess go ahead, too.

Thanks in advance and God's Blessings on you all.

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If I understand right and it won't go on all the way the common issues are is the key the right size/depth? Sometimes if the key is too tall it will rock forward to let it go on a ways but doesn't have room for it to fully seat in order to finish going on. My other first check which you may have already done is if it has any scarring or is buggered up at all near the end of the shaft or key-way?

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The crank shaft on my Farmall A is not threaded in the end ,the pulley relies on a tight fit. I had to warm the pulley up(not too hot as it will damage the front seal) and I had to file the key slightly to allow the pulley to fit correctly. Once I had done that it slipped on easily and I gave it a light tap with a block of wood just to make sure it was fully seated. I did try a new aftermarket pulley that didn't have the set screw but it would work loose and come of the crank so I found an original pulley with set screw and have had no problems since. 

I would measure the crank shaft and the pulley to make sure every thing is correct. I wouldn't take much to stop the pulley from fitting. If you remove the key will the pulley slide any further on to the shaft? Mine would go on about 3/4 of the way on.  Does the key fit in the keyway properly? I would guess the key is what the problem is, if the pulley is the correct one for tractor.


Farmall A 20-11-11 001.JPG


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Going from what you've said over the last couple of days, I determined yesterday afternoon that the pulley was going ON the shaft, come **** or high water. And go it did!

I pulled out the tap & die set again and kept pushing and turning and cutting until I cut through and cleaned up the thread. They were boogered up just enough to prevent the half inch stock from starting. Once I get them cleaned up with a healthy dose of brake cleaner to wash out the shavings, I sprayed in some white lithium grease, screwed in the half inch althread, complete with the pulley, several assorted sizes of big washers, followed by the nut and BAM! Magic happened :-) 

Within two hours of getting the pulley on, it was in time, valves set, and with a couple squirts of gas into the cylinders, she popped off, so the old girl has life once again.

Photos as soon as I get everything finished up. Many, many thanks to all who've taken the time- and persistence- to help a youngster through to success and co completion.

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