What year is this 112 grader?

Sorry I meant 212😞

hello Rd6 plower , i couldn't find serial number that high for the 1r ,last one built in 1944 maybe as high as 1r1500?,someone may have more info ,bruce oz

The 1Rxxxx-212 model seems to have a messed up serial number publication. I have one list (probably sames as bruce oz) that tops out with sr. # 1130-up in 1944.
I also have reliable information that the model continued to 1947 but I don't have a break down by years.

Could use some new info on this one😊 😊

The list I have (same one as yours I guess) switches to the 1U series of tandem drive diesel 212's starting in 1946 going through 1947. Shows no production at all in 1945 between the 1R and 1U series. so there's certainly some room for production in those years.

But using the 1R8973 as the very last one produced sometime in 1947 would mean over 2000 graders produced each year between 1944 and 1947. The maximum number I can show of all types of gas, diesel, single or tandem drive being produced in any pre-war/war year is 483 in 1941 and after the war, production climbing to 946 of the 9T's in 1950, and about the same again in 1951, before falling again to around 800 in 1952 and to about 400 a year in '53 and '54.

So I expect there is a mistake somewhere and the grader in question was mis-stamped or some kind of special etc.

Perhaps an engine swap? Were there any other D3400's with the 1R serial numbers?

RD6 Plower - please recheck your serial number (1R8973) on both engine and chassis.

My records also show that for the 1R series (212 Diesel tandem), the last built was 1R1130 in 1943. There were no 212's built until the 1U series starting in 1946.

Note that a similar event happened on the 112 Graders. For the 2M series (112 Diesel tandem), the last built was 2M1516 in 1942. Then there was a skip until the 3U series beginning in 1947.

It appears that during the war years and a few years after, Caterpillar only offered the No. 12 grader. This model was manufactured as 9K and 7T series for years 1938 thru 1947.

Thanks for the info:
My list shows #1129 for 1943, then 1130 - up for 1944. Was there any "up" and is this correct or "who knows"😊

OM - As you know, some of the published Caterpillar Serial Number records have errors. Another check I use are parts catalogs. In the case of the 1R series the only parts catalogs offered are for 1R1 to 1R1130.

My Cat SNID book shows a 212 2R grader that came out in 1940 also so don,t know the difference of the 1R and the 2R.

Hi SJ,
The 2R is a gas model.

KCB,
That cinches it😊 I often use the parts catalog serial number range as the final word. Thanks