The Ford Barn

37 Coupe · 11-07-2018, 09:43 AM

I wonder if Ford manufactured their transmission cases for the Model A with some nickle or some other element with cast iron or are they some kind of cast steel? The reason I make this point is the case and the rear bearing retainer seemed tougher to paint than the engine block and bellhousings that I know are cast iron. I used the Bill Hirsch engine paint,states no primer needed on cast iron but it does on steel, and it goes on great but the transmission case and retainer were like trying to paint chrome,two coats.

BRENT in 10-uh-C · 11-07-2018, 10:44 AM

Quote:

Originally Posted by 37 Coupe

I wonder if Ford manufactured their transmission cases for the Model A with some nickle or some other element with cast iron or are they some kind of cast steel? The reason I make this point is the case and the rear bearing retainer seemed tougher to paint than the engine block and bellhousings that I know are cast iron. I used the Bill Hirsch engine paint,states no primer needed on cast iron but it does on steel, and it goes on great but the transmission case and retainer were like trying to paint chrome,two coats.

It likely has to do with more porosity, cleanliness, and the paint. First, the reason why steel is tougher for adhesion (-hence the primer) is because of less porosity for the paint to adhere to. As for needing two coats for coverage vs. one, that likely has to do with how well the pigments were mixed with the binders inside the can. Naturally if the surfaces are not free of oils, then adhesion of the paint would naturally be an issue too.

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MikeK · 11-07-2018, 08:35 PM

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The iron for both the blocks and trans cases (as well as most other gray iron parts) was fed to the foundry pouring line at the Rouge from several huge cupola furnaces. The iron for these parts was unalloyed and nothing to write home about. By today's standards it would vary by batch somewhere between class 20 and 30.

The only 'add' to the makeup of the cupola charge layers was silicon, used to stabilize the carbon to promote flake graphite rather than carbide precipitation upon solidification.

The stuff machined like butter with just simple carbon steel tool bits. No cobalt steel or carbide bits needed. You could carve your initials into the castings with a scout pocket knife.

11-07-2018, 09:43 AM	#1
37 Coupe Senior Member Join Date: May 2010 Posts: 1,835	Transmission case iron? I wonder if Ford manufactured their transmission cases for the Model A with some nickle or some other element with cast iron or are they some kind of cast steel? The reason I make this point is the case and the rear bearing retainer seemed tougher to paint than the engine block and bellhousings that I know are cast iron. I used the Bill Hirsch engine paint,states no primer needed on cast iron but it does on steel, and it goes on great but the transmission case and retainer were like trying to paint chrome,two coats. __________________ "Never complain,never explain"... Henry Ford II

11-07-2018, 08:35 PM	#3
MikeK Senior Member Join Date: May 2010 Location: Windy City Posts: 2,919	Re: Transmission case iron? Sponsored Links (Register now to hide all advertisements) The iron for both the blocks and trans cases (as well as most other gray iron parts) was fed to the foundry pouring line at the Rouge from several huge cupola furnaces. The iron for these parts was unalloyed and nothing to write home about. By today's standards it would vary by batch somewhere between class 20 and 30. The only 'add' to the makeup of the cupola charge layers was silicon, used to stabilize the carbon to promote flake graphite rather than carbide precipitation upon solidification. The stuff machined like butter with just simple carbon steel tool bits. No cobalt steel or carbide bits needed. You could carve your initials into the castings with a scout pocket knife.