At the end of my rope

[Texas Tony]

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. 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.

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 beat me up 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 you're entitled to your opinion, too.

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

[Jim Becker]

My first thought is that it should be 1/2 coarse thread, but I could be wrong. Your pulley doesn't have a setscrew does it? If so, it needs to be backed fully out. The setscrew version of the pulley should go on fairly easy. You need to get a piece of all-thread (whatever size/thread it takes) screwed fully into the crankshaft. Have flat washers and nut ready to go. Heat the pulley in an oven at about 225 to 250 degrees. A toaster oven will work OK if the kitchen isn't nearby. Let it sit in the oven long enough to thoroughly heat-soak. Use oven mitts to put the pulley on the crankshaft and pull it the rest of the way onto the crankshaft with the washers and nut. Work quickly as the pulley will loose heat quickly as soon as it gets much contact on the crankshaft. If you can't get the all-thread pulling system set up (e.g. if crankshaft has no threads), do the heating the same way and drive the pulley on using a hardwood block on the hub and hit it with a fairly hefty hammer.

Be sure to leave the front cover bolts loose until the pulley is in place.

[Texas Tony]

I tried 1/2" 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 we split two pieces of 2x6, and it finally stopped as I said before, with roughly 3/4" left to go.

I believe I'm going to do some research this morning and see if I can find a metric bolt or althread that would be between 1/2" and 7/16. I'm too far into this and have too much riding on this project to surrender. And I appreciate your input, Mr. Becker, and thank you for taking the time to help. Your effort is greatly valued and most welcome.

[ShawnAgne]

Can you just retap it? I know I had some holes on my Cub that didn't let a screw go in until I retapped the hole.

[Jim Becker]

Something isn't right here. The setscrew style pulley shouldn't go on that hard. The threads in the crankshaft aren't metric. You probably need to find somebody local that is familiar with these things to look at it.

[Urbish]

Something isn't right here. The setscrew style pulley shouldn't go on that hard. The threads in the crankshaft aren't metric. You probably need to find somebody local that is familiar with these things to look at it.

I can appreciate your urgency to get this thing going for your kids, but I think you'll need some help from someone familiar with the application. I know it can be tempting to re-tap it or something, but you don't want to do anything rash that will end up screwing up your crankshaft.

[Texas Tony]

Can you just retap it? I know I had some holes on my Cub that didn't let a screw go in until I retapped the hole.

I'm not above re-tapping, and if it were just cleaning up the threads, I'd be ok with it, but as far as re-tapping a hole goes, I'm man enough to admit when I'm not comfortable with something and I'll stop. If bad comes to worse, then yes I will get it done.

[Texas Tony]

Something isn't right here. The setscrew style pulley shouldn't go on that hard. The threads in the crankshaft aren't metric. You probably need to find somebody local that is familiar with these things to look at it.

I was thinking that perhaps a metric size would fit. I know something made in 1940 in the USA is not going to have anything metric on it, but maybe I could get a metric size between the two sizes I've already tried and that might work. I'm going to talk to a man this afternoon who might be some help. He has a machine shop and does a lot of custom welding and metal work.

[Texas Tony]

Something isn't right here. The setscrew style pulley shouldn't go on that hard. The threads in the crankshaft aren't metric. You probably need to find somebody local that is familiar with these things to look at it.

I can appreciate your urgency to get this thing going for your kids, but I think you'll need some help from someone familiar with the application. I know it can be tempting to re-tap it or something, but you don't want to do anything rash that will end up screwing up your crankshaft.

I agree with re-tapping and am going to hold off on that option until there is nothing left to try. I'm going to ask a fellow this afternoon who has a machine and tractor shop and see what he says. Thank you for all of the advice and help.

[ShawnAgne]

Can you just retap it? I know I had some holes on my Cub that didn't let a screw go in until I retapped the hole.

I'm not above re-tapping, and if it were just cleaning up the threads, I'd be ok with it, but as far as re-tapping a hole goes, I'm man enough to admit when I'm not comfortable with something and I'll stop. If bad comes to worse, then yes I will get it done.

Yeah wasn't refering to cutting new threads just cleaning them up. I chased threads on several of my screws and mounting holes which were turning way tough and then they went in easy. Hope you figure it out, remember about a year ago I was in the same situation trying to get the new motor in my Cub and was very frustrated/upset.

[Texas Tony]

Gentlemen:

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 Hell 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.

[ShawnAgne]

Good, that is what I was figuring the problem was. Like I've said I've had several threads on the Cub and 300 that were just like that and chasing and cleaning up the threads fixes a lot of things.

[Texas Tony]

The machine shop was also supposed to chase all the threads. Yeah, that didn't happen. I'm so glad that this forum is here and hope I can return the many favors and courtesies extended to me during this process. Thanks again, Shawn.