Model A crankshafts

Tstoner · Apr 6, 2023

This question is more about curiosity as I am trying to learn more about these old tractors. I have a 44 A I am restoring I recently went to install my clutch driver and found a crack so I bought a new (used) one noticed the new one had a rivot in the splines I made sure it is the same part and casting number as original. I looked at my old driver and could see where there used to be a rivot but my crankshaft doesn't have a cut out or indent for the rivot to index with. Did jd use different cranks for the same style model A?

HFP · Apr 6, 2023

I'm not sure at what point in time that rivet was added, but my 1936 USA has one of the splines ground down on the end to accommodate the
exact situation you are in now. It hasn't created any issues.

Tstoner · Apr 6, 2023

(quoted from post at 06:55:03 04/06/23) I'm not sure at what point in time that rivet was added, but my 1936 USA has one of the splines ground down on the end to accommodate the
exact situation you are in now. It hasn't created any issues.

I think I'm just going to file the rivot out of the driver and call it a day I was more or less just curious. I've seen cranks with the same casting and part number have the Grove for the rivot and I've seen some without

Mike(NEOhio) · Apr 6, 2023

Go by the mark. Just compare the new one with the old to be sure the mark is in the right place.

susandiane · Apr 6, 2023

Assuming the parts are otherwise identical, the new driver must be orientated exactly as the cracked one was. It's also a counterweight and if it isn't right you'll have a 2 cylinder version of the New Madrid
earthquake. I've read here how to orient the driver with the flywheel counterweight, but I don't remember how. When you get it right, be sure and stamp some clear witness marks on it.

Someone who knows this, chime in and help this fellow addict out.

Tstoner · Apr 6, 2023

The new one doesn't have a mark on it but yes I was going to line them up and I think the counter weight on the driver matches the rod journal on number one cylinder? I could be wrong

Tstoner · Apr 6, 2023

(quoted from post at 07:48:12 04/06/23)
I also should mention as far as dimensions the parts are identical. But the outer portion of the original is solid all the way around and the new one is open on the side opposite of the counter weight if that makes sense

Assuming the parts are otherwise identical, the new driver must be orientated exactly as the cracked one was. It's also a counterweight and if it isn't right you'll have a 2 cylinder version of the New Madrid
earthquake. I've read here how to orient the driver with the flywheel counterweight, but I don't remember how. When you get it right, be sure and stamp some clear witness marks on it.

Someone who knows this, chime in and help this fellow addict out.

Mike(NEOhio) · Apr 6, 2023

From a 51. Yours may be different. A little fuzzy but you can just see the bottom of the V under the broken tooth on the right.

Mike N Mo · Apr 6, 2023

When in doubt about proper timing for a clutch driver or flywheel, always put the counterweight for either one 180* from the crank throw closest to it. In other words, with the right side piston at top dead center, the counterweight on the clutch driver should be at 9 o'clock.

Tstoner · Apr 6, 2023

(quoted from post at 15:32:43 04/06/23) When in doubt about proper timing for a clutch driver or flywheel, always put the counterweight for either one 180* from the crank throw closest to it. In other words, with the right side piston at top dead center, the counterweight on the clutch driver should be at 9 o'clock.

Thank you for the help. One more question how important are the lead washers on the dust shield that the belt pulley slides over? It's gets bolted to the gear cover case with a gasket?

Model A crankshafts

Tstoner

Member

HFP

Member

Tstoner

Member

Mike(NEOhio)

Well-known Member

susandiane

Member

Tstoner

Member

Tstoner

Member

Mike(NEOhio)

Well-known Member

Mike N Mo

Member

Tstoner

Member

Similar threads