The Ford Barn

Barn Junk · 11-27-2012, 03:22 PM

Sorting through some parts and noticed two different mainshafts used, 81A-7061 for 1939-1942 and 51A-7061 for 1946-1948. Also the second gears were changed at the same time, 81A-7102 for 1939-1942 and 51A-7102 for 1946-1948.
The 81A design incorporates a spacer held in place with a pin in the mainshaft. The 51A design extends the main shaft and eliminates the spacer.
The 81A 2nd gear has a wide thrust surface to fit the spacer. The 51A 2nd gear has a narrow thrust surface that rides directly on the main shaft.
My question is, "Can the different 2nd gears be swapped or interchanged and function correctly between the two different mainshaft designs?"

11-27-2012, 03:22 PM	#1
Barn Junk Senior Member Join Date: May 2010 Location: WA state Posts: 771	1939-1948 2nd Gears Interchangeable? Sorting through some parts and noticed two different mainshafts used, 81A-7061 for 1939-1942 and 51A-7061 for 1946-1948. Also the second gears were changed at the same time, 81A-7102 for 1939-1942 and 51A-7102 for 1946-1948. The 81A design incorporates a spacer held in place with a pin in the mainshaft. The 51A design extends the main shaft and eliminates the spacer. The 81A 2nd gear has a wide thrust surface to fit the spacer. The 51A 2nd gear has a narrow thrust surface that rides directly on the main shaft. My question is, "Can the different 2nd gears be swapped or interchanged and function correctly between the two different mainshaft designs?"