I have a Caterpillar D-8 with Chassis Serial Number 1A-79 and the engine serial number "Power Unit Number 1A469IOK". The only thing I've been able to find about these serial numbers are that the 1-A serial numbers were experimental tractors. Can anyone give me some information on this tractor? I'm interested in knowing what year it is and what value it might have.

On this thread - Post #20 - I added a couple of pictures.

I can,t help you on those numbers as I never heard of them but back in about late 1956 & 1957 Cat sent an experimental tractor to the dealer I worked for & it was labeled EX-1 & was a 15A D8 tractor other than the transmission & that,s when they were developing the power shift transmission. When it was all done we had I believe it was 4 Ex tractors with exp. tran. in them & the last one or two were about what the 46A trans.& tractor turned out to be. That first one was a 5 speed with no torque convertor & boy what a fast machine esp. from forward to reverse. Cat sent a factory engineer here & he lived with it till the program was completed with all the EXers. Him & his family lived here in Dallas Pa. near me & for a while after the D8 EX. job was completed.

What about pictures and description of equipment etc the tractor has. Where is it, what was it doing etc.?

CC I don,t know where beaver could have got his tractor but the ones they sent to the dealer I worked for they were all sent back to the factory after the testing.They were put out on jobs esp. in coal strippings where they could get the most hours in the shortest time.After so many hours on them they were brought into the shop & esp. the trans.& were disassembled & the engineer went over it with a fine tooth comb & took all measurements of things that could wear & the reports were sent back to the factory.Some other things like steering clutches etc. were also checked & reports filled out on their condition. I have no idea what ever became of the tractors after they returned to the Cat factory in Peoria.

abeaver,
My Cat serial number index lists the 1A series as a 786 wheel tractor?

I did check the list of military model serial numbers, but there is no reference to this number. Does anyone know any different?

A number of 14A tractors were assembled in England, at the Cat Desford factory near Leicester, from components shipped in from the US. These tractors were assigned an S serial number, but no records are know to exist which detail the extent of the production run.

I think you better find another number because that no. is a haul truck and all the experimental machines that Ive seen are labeled EXP-1 ect and nothing to do with model. I know where there are few EXP-1,2,3s all diff machines like a big20 a D2and a 6G30 and its not uncomon to find them in this area because when they were done with tests most went to C L Bests ranch in Woodland Ca and put to work

the 1a1 serie is 8 Ton Goer (MIL)

I think there was a article in a very old cat club newsletter about 1A#'s being test machines. I will look tonight leroy

abeaver,

Can you post a picture of your tractor to help ID it?

1A numbers are used on test machines. They were used at places like the Peoria and Tucson Proving Grounds up until a few years ago. Some of the last 1A numbers were into the 13000's. In the 1950's there are pics of tractors with 1A numbers in the 1200's to 1300's. You can see some in the historical Cat books like 75th ann. book and prob the 50th ann. book.
I'd guess if you really have 1A-79 it would be from the 1940's.

Here is a pic of a test truck with a grader in the background. The truck is blocking the 1st number of the 1A so don't know if it is 1A101 or 1A901
Muzz