What's involved in swapping Farmall A PTO shafts?

[Capnball]

So, I'm about to sell my parts tractor, and I want the PTO shaft out of it, as mine is, while still very useable, ever so slightly bent. Any special spacing/gear mesh/shimming issues I need to be aware of, like there's supposed to be with adding a belt pulley unit? Both tractors are setup the same- PTO, but no pulley unit.

[Jim Becker]

No particular complications. Take a look at the exploded view in the parts catalog and it is pretty straightforward. There were noteworthy changes to the PTO over time. That shaft changed from 1-1/8 to 1-3/8 but I believe it interchanges with all versions. The easy way to change it would be to swap the entire PTO, has to come off to change the shaft anyway. I would be hesitant to put a late style PTO on an early transmission, but they will interchange.

[Capnball]

No particular complications. Take a look at the exploded view in the parts catalog and it is pretty straightforward. There were noteworthy changes to the PTO over time. That shaft changed from 1-1/8 to 1-3/8 but I believe it interchanges with all versions. The easy way to change it would be to swap the entire PTO, has to come off to change the shaft anyway. I would be hesitant to put a late style PTO on an early transmission, but they will interchange.

Why would you be hesitant? I personally am, because I want to keep my tractor as original as possible. I would rather just swap the shaft if at all possible. The parts tractor ('46) has the 1-3/8" shaft, while my '41 has the smaller shaft. Another thing I might mention is that I do plan on adding a belt pulley unit when I find one.

[Jim Becker]

First off, the transmission and PTO changed at serial 66671, mid-year 1941. So maybe you have the later style anyway. The early style had no oil slinger in the transmission but had one in the PTO. So when doing stationary work (typically belt work) the PTO oiled the transmission. The later transmission had an oil slinger but the PTO didn't. So when doing stationary work the transmission oiled the PTO. If you put a late PTO on an early transmission, you have no oil slinger. Will it ever matter? Probably not.

BY the way, the two styles of PTO require different pulley attachments. I don't think they mix.

[Capnball]

First off, the transmission and PTO changed at serial 66671, mid-year 1941. So maybe you have the later style anyway. The early style had no oil slinger in the transmission but had one in the PTO. So when doing stationary work (typically belt work) the PTO oiled the transmission. The later transmission had an oil slinger but the PTO didn't. So when doing stationary work the transmission oiled the PTO. If you put a late PTO on an early transmission, you have no oil slinger. Will it ever matter? Probably not.

BY the way, the two styles of PTO require different pulley attachments. I don't think they mix.

Huh. Good info. So, being as my tractor's serial is 79,xxx, think I have anything to worry about?

[Jim Becker]

They are probably identical. You should be able to confirm by the part numbers on the housings.

[Capnball]

They are probably identical. You should be able to confirm by the part numbers on the housings.

I checked, and yes they are. I wound up taking the '41's PTO out, because one of the housing bolts was missing, and needed to clean the mud-dauber mud out with drill and tap in order to replace the bolt with one from the donor tractor.

I chickened out of selling the whole parts tractor, as well as swapping the PTO shafts- I decided to wait and replace the bent one with a 1-1/8" shaft.

[Jim Becker]

I'd swap it. There was a field change package to upgrade to the newer PTO standard. It included the 1-3/8 shaft and a hitch plate.

[Capnball]

I'd swap it. There was a field change package to upgrade to the newer PTO standard. It included the 1-3/8 shaft and a hitch plate.

Ok. Hitch plate?

[Jim Becker]

One of these.

http://www.ebay.com/itm/Farmall-IH-Tractor-drawbar-hitch-plate-bolts-/272207904159

[havoc1482]

The wider end of it goes through the draw bar, where the two holes are. The rest of it sticks off the back and you can put a ball hitch or something into it. I have a centerline hole in my Super A drawbar that I can drop a 2" ball hitch through so I don't need one of those. I don't quite remember, but I believe the centerline hole for the As drawbar was too small to really put anything through it.

[Daniel H.]

I think the intent of the plate was to put the hitch point the correct distance back from the end of the PTO shaft to match new ASAE standards, also why the shaft was changed to 1-3/8 diameter.