Farmall M serial number and year made

Hello! A friend of mine has a Farmall M tractor with an unreadable tag. The engine number looks like FRKM272809. The axle trumpet has the letter L on the small tag. I would be grateful for any info that can be had from the engine number. Thank you.

According to Serial Numbers under Research & Info to the left of this page, the engine was manufactured in 1941. If you are indicating a date on the axle such as 3#16#L, the axle would have been cast in 1942.

If engine is original to rest of tractor, tractor serial # would be 285809 a late 51 model.

as slater said it's a '51, but the prefix is FBKM just so you know for further refrens. thses numbers and letters on these old tractors can be hard to read. you can go to link_disallowed and order a new tag for a bout $25 and have it engraved, the prefix on that would be FBK.

-Randy-

I only missed by one digit.

I only missed by one digit.

Gotta differ with ya on this one. See the link. Look at 1952 Engines March 31. They started with FBKM 285001 after March 31, 1952. That would make it a 1952 tractor at the least. Then go to the next page, 1952, which lists both engine and chassis numbers. The first serial number on an M for April 1952 was 295555. So also, to a point made elsewhere in the thread, FBKM is a valid prefix but would not have occurred before the end of March 1952 and, in fact, the number in question would seem to indicate the motor could only have come off the line in April of '52, as they started with a much lower, four-dighit number in May. Couple that with the L casting code, and I don't know how anybody could suggest a date for sure, never mind a chassis serial number for a tractor that may have had a replacement motor dropped in.

I know I must be building a reputation as something of a crank about the issue. I dont know you at all, so please believe that I'm not trying to make this about you or your character, but the IH records are so spotty that, in those cases where the serial number did not routinely match that of the chassis, it is nigh impossible to interpolate and come up with a correct chassis serial number on the basis of the number on the motor.

Even in the cases where the numbers agreed, it's sketchy at best to suggest a year or serial number for the chassis when the casting codes on the chassis don't jibe with the serial number on the motor. And in cases where chassis and motor numbers were known to be out of synch, there is no pattern or definite interval to the disparate numbers that would allow one to even suggest an actual number for the chassis.
IH records at UWisco

Your M engine serial number shows it is a 1951.

FBKM is actually a good prefix. See my post below.

Have to differ with you also, don't mind discussing things. I could be wrong and could learn something. I have looked at the records before and unless I missed something it showes the first tractor in jan. 52 as FBKM engine serial # being 277923 and first tractor regular gas M FBK serial # 290923. Think cotton harvestors and modified M based tractors was the only thing after the end of march 52. No regular M tractors after march. Unless I'm mistaken he said the engine # was 272809 so from past work on this I put the engine serial # 13000 higher than engine for that engine # range. I also said if engine is original to tractor. If not he will have to determan that by date codes or cast # suffixes sometimes. Here' a real tractor # 286713 engine 273713. If you notice the engine # is higher than his. For some reason the MD tractor serial numbers for start of Jan. 52 are a good bit lower than gas. 285211. I welcome anyone with a original M tractor around serial 285809 to post one serial or the other and see how many times I get the other # to check it out if you like. When you see the M numbers drop back to 3 digits in 1952, I think thats SM tractor serial numbers even though they don't show it on there.

i know, i was stating it because in the original post Bjarne had put "FRKM272809" just so he would know that R should be a B.

Ooopppss on me! Good catch!

Good discussion, agreed, but I'm still at odds.

I'll grant that the online records for '51 show only chassis serial numbers, and that the records, at least for the first couple months of '52 show motor serial numbers exactly 13,000 higher than the motors, just as the actual tractor you cite.

Put that together with the Motor serial number from the records for '52, and we have a problem.

Take it one step further and refer to Guy Fay's data book, where he lists two possible sets of serial numbers for later production Ms (one set agrees with the online records at Wisconsin, the other is different, but I trust Guy and assume he had conflicting sources, else he'd not have noted the disparity). Has your research resolved that issue?

Couple that with the fact that Bjarne is looking at a tractor with an "L" that sounds very much like it could be a casting code, which would be good for '42, and I'd want to know a LOT more before "assigning" a chassis serial number with no more information than we have and the disparity and potential for error in the data.

First off I have said in both posts if engine is original to tractor, if not of coarse there's no way to know tractor serial #. The engine starting numbers are there in the records. The first M engine built in november of 51 is listed as serial # 271158 and first in Dec. is 274940 and posters # is 272809 so his engine was installed in Nov. correct? Tractor serial # for start of Nov. and Dec. is 284158 and 287940. So his tractor serial # if original to the engine would be between those to numbers. I been interested in little differences and why on these tractors for years. The more I learn the more questions comes up that I can't find a answer to. I have learned there's inconsist information in IH records and I think there's some in the serial # records on line. Guy Fays has a good book but there's mistakes in it which I don't fault him in all that information. I can't even make a post here without a mistake sometimes. I'm not saying I can match all engine and chassis serial numbers but from later 49 on up I can 99% of the time. Before that most times from engine # I can tell year and month tractor was built. If I could look at tractor in question I could tell you in a couple of minutes if engine was original or other parts. Even if his axle housing has a L code on it that don't tell much. Lots of M out there with axle housings replaced with used parts. Need to check more of tractor to say on that. You said I was way off on the numbers, I want to see something to back it up. Again everthing I said on the tractor numbers depends on original engine and tractor sold togeather. Still say engine # 272809 came in tractor # 285809.

This has degenerated into something I didn't want it to become.

I didn't say that "you were way off on the numbers." I pointed out that your numbers were consistent as far as they went. But you keep citing the 1951 numbers. If you look at the 1952 numbers you will see that they overlap considerably, which I think might be the source of the problem Guy Fay cites as well as our being at odds. As far as that goes, we are only disagreeing (and I hope not fighting) about whether it's a '51 or a '52 motor.

Then the casting code comes in. Did the axle housing get replaced or the motor? You don't know, and neither do I.

I agree, it would require a closer look at the actual tractor and reference to the records and a lot more information than what we have been given about this tractor, but I would argue that that should be done before we give somebody a serial number that they can go have stamped on a plate and represent it to be the original chassis number of the tractor.

Bjarne, please check casting codes on the rest of the tractor to help clarify the discussion below. They will be in the form of 5*8*U, or May 8, 1951. U and W are 1951, X is 1952. Apparently yours was made in 1 of those 2 years. Casting codes are on most parts. Compare the engine casting code with other parts. If the L is in the form of month*day*L, it was cast in 1942. If there are no other L's then it is a replacement. One other thing. Some SUPER M's were built in Louisville. A stand alone L is an indication that the part was cast in Louisville (although some parts could have been shipped to Louisville and then assembled) The FBK prefix indicates that you have an M not a Super M (at least the engine is from an M), so if the L on the axle housing is NOT in the form of month*day*L, and is by itself, that casting may be from a Super M.

I agree that the serial # I posted would be wrong to put on tractor if engine is not original or chassis is not original to engine. Also thats why I stressed if original in every post. When I told him the chassis # would be 285809 if original tractor. I can't find were the 51 and 52 tractor or engine serial numbers overlap if you looking at the IH monthly starting numbers for M tractors and engines. Think part of the problem with 51 ending numbers is the last MD in 51 may have been 285099 and the M gas numbers were around 5000 or more higher at end of 51. These numbers get lumped togeather under M and the problem arises. Another problem is IH didn't always use calender year for everything. I may be hardheaded but have no ill will toward you. The way I look at IH records is the first carburetor tractor M built for the month is Nov. 51 284158, dec. 287940, 1952 jan. 290923, feb. 294028, mar. 295555. MD tractors start of nov. 1951 283664 dec. 283945 jan. 52 285211 feb. 285488, march 298021. In early post I didn't mention MV was made into april 52. Going to need you to point out to me were the M carbureted tractor serial numbers overlap for 51 and 52. If they do I'm going to feel like the dumbest person around.

The second line under engines for each year lists Mod M under Model, but the column under tractor is blank.

Further down, they list M (way down below MVs, MDs . . .) in the Model column and FBKM. That's where the overlap is, between the Mod M with the blank column and the M under Model with the FBKM in the tractor column. Which one was the M???

It's those two sets of number, both identified as going into Ms (in very similar quantities) that overlap.

That said, I'll eat some crow and allow that the motor in question is from late '51, and can only speculate that the memo from March '52 authorizing the FMBK prefix could have been a retro-active affair as the records indicate the prefix and even the numbers in the memo predating it by fifteen months at least. Very odd.

But again, we still have two sets of serial numbers for motors on Ms during this period, and the two motors have different spans between the first number of successive months, precluding any conclusion on a chassis number based on the engine number.

Mod. M to the best of my knowlege stands for modified M tractor chassis for a special use, not a regular M. They were made along with modified M engines later than the other M series models. Get back later on what I think your seeing on the engines. Its going to take some time and I'm Going to bed.

My bedtime, too.

Again, I don't mean to beat you over the head (or the subject to death) but the records on the M are ambiguous enough, for that period especially, that I question assigning a chassis serial number at this late date, to any tractor based on the number on the motor. It would be really nice if IH was still around, but even then, it would probably be just one old eccentric bachelor left hanging around in the production manager's office that could explain what those numbers mean and, if it turned out that he had died, we'd be right back in the soup you and I are swimming in.

In those cases of missing plates, even on the earlier tractors (like the As and Bs that I'm more familiar with where the numbers DID run together for many years, but eventually got apart), I can sympathize with the folks who want to have a plate, but even in those cases, I encourage those that want to have a new plate made up to have it made with only the first two or three digits, only as far as they can go for a given year and only if the casting dates are reasonably consistent with their motor number, and fill in the rest with Xs.

CNKS's point about the L indicating a Louisville casting has possibilities, too.

G'night!

Good morning, after a nights sleep I decided to try and slow down or stop my postings. Looks like I'm hoging the board with posts that make sence to me but just look like crazy ramblings to someone else. My email is open if you want to discuss this more. I have no problem and if we were in person discussing above posts I would be smilling a lot. I will add that on farmall M I noticed a corlation for some serial numbers long before I heard of IH serial # records. Started keeping track of numbers and I based my statment that his engine would have came in the tractor # I posted on based that past experience. In the engine serial # window of his tractor I was 99.9 % sure of what the tractor serial # would Be (provided engine and rest of tractor left factory together) so that was my answer. One other thing I didn't mention last night left axle housings have LH on housings after part #. L is plainly visuable on most. I dont know if he was looking at a date code or even sure it was a axle housing. Only thing I'm willing to bet money on is what tractor # that engine came in if original M engine. Whether IH called the tractor a 51 or a 52 model when they sold it I can't say for sure. Unless it was moved quick Probably dealer sold it as a 52. Good day