Need Help Identifying Caterpillar THIRTY - 1925 ?

Garlic Pete is correct about the casting numbers I believe that this 30 is 1928 or later going by the large track adjuster springs and manifold pics a 1925 would also have a tube style radiator once the fender tags go missing it is very difficult to date a 30

^^ Agreed, has a wide seat which is a 1926+, big springs on the roller frame, and new style radiator, newer manifold. Looks like a nice find though! Mine's currently undergoing surgery as well.

My two 30s are a bit different. The oldest is PS 75 the number is stamped in the casting right behind the seat .
Terry

[quote="Garlic Pete"]All of the pictures you posted are of part number or casting number. Caterpillar almost always casts the part number into their parts. Each part has a unique number. Most metal parts also have a casting number cast into them, which is different than the part number. Just a little after your tractor was made, Caterpillar standardized on a system of a number, a letter and four numbers for the part number. I believe the pictures you posted are of part numbers, rather than casting numbers, though.

As gary ca noted and pictured, tractor serial numbers are generally stamped into a tag, which is screwed onto the tractor. The serial number is also usually stamped into the steel underneath that tag, in case the tag gets damaged or lost. On the Thirtys, those tags were large brass tags, about four or five inches square, which were attached to the tail end of the fenders. Unfortunately, this was usually the first area to get torn up on a tractor and those fenders were usually either bobbed or removed entirely, as they have been on your tractor.

There are a number of places that serial numbers can be stamped on the tractor besides on the fenders. As gary noted, one of the most common areas is near the number 4 cylinder on a flat spot on the block. There are a number of other places, though, and there didn't seem to be a standard for which place they chose to stamp those numbers. I know another common place is on the right side of the transmission case, right up near where it bolts to the bell housing. This place is really hard to see and clean up because it is right behind the track and also behind the side panel which is supposed to be there. There are several other common places, though. Someone more familiar with the Thirty will probably chime in here and give you all the places to look.

Caterpillar Thirty serial numbers generally begin with an S or a PS. The S tractors were built in Stockton and the PS tractors were built in Peoria. Caterpillar Thirtys were built during the period right after the 1925 merger while Caterpillar initially operated in Stockton, California. Shortly after the merger, Caterpillar looked for a new factory location and settled on Peoria, Illinois. There was a short while that they operated both factories at the same time.

Pete.[/quote]

Pete,

Just today, a Quinn employee who also collects told me the S was for San Leandro and PS Peoria. I have no idea one way or the other. Just passing it on.

I looked at a THIRTY this week and then three more today. I can't read much of anything on the three today after checking behind the fourth jug on the flat spot. All three tractors are missing the fender plate. The one that is for sale that I looked at on Friday had this stamped on the flat spot (and no fender plate, of course)

30
4
18
29

The stampings as shown above would be if you were sitting in the seat and on the right edge of the engine block. These almost seem like they show the date of manufacture. I could not even faintly see an S or PS on any of the four tractors that I looked at. As someone already posted, the THIRTYs are hard to trace once that fender plate goes away.

Can anyone add to the discussion on the stampings above?

Jan