farmall A serial number

I recently got a hold of an a with a woods mower on it. And I have been trying to locate the serial number so I can find out what year it was built.
I can find no legend plate on the tractor?
Anyone no where I should be looking?
Thanks

look under the seat. it's on the left upright faceing inward to the rear. above the belt pully

Under the Seat you should fine the serial number plate. The use the "serial numbers reference in the left chrome.

thanks I will have a look at it when I get home today.

If the plate the others describe on the left seat support is not there, look on the motor, at the top edge of the block and just below the #1 spark plug for a machined flat spot. It may be obscured a little by the throttle control rod and be covered in oil and gunk, but there's a serial number there, too, that, when new, matched the chassis serial number on the tractor.

You can also make an educated guess by looking at any casting date codes. These are found on the larger cast parts like the crankcase, transmission, final drives and sometimes the torque tube. They look like a flat strip about three inches long with the impression of screw heads and numbers and letteres, as in ##-##-X, where the numbers (month and day), and the final letter (year) indicate the date that that part was cast. For the years that the A was made, the years ran consecutively from I for 1939 through Q for 1947. As a f'rinstance, 10-16-K would be October 16, 1941. It would not be unusual to find a spread of six months between some of the dates, and you could safely assume that the tractor might not have been assembled for a couple of months after the newest date that you can find. Using that same 10-16-K, the tractor could be a late '41 or just as easily an early '42.

Relying on just the motor serial number, if that's all you have, can be a little tricky as a lot of motors have been changed out over the years, but if the serial number is consistent with the years of the cstings aon other parts of the tractor, and the casting code on the crankcase is within a few months of those elsewhere on the tractor, it wouldn't be unreasonable to assume the morote is original, in which case the serial number will help you nail down the year.

Apart from a few changes made over the course of the first 90,000 or so that were made -- the magneto grounding mechanism, provision for a starter in the torque tube, and the height of the oil filter and housing are three that come to mind -- the As were otherwise pretty much the same from year to year.