Hey everyone. First post, but I've been reading a lot of awesome posts that have helped me learn about these machines. I'm a rancher and I need to build some roads so I'm picking up a 120 that another rancher has. I was curious if anyone was able to tell me what year it is. I think I have it narrowed down to 1969-1972 based on a few of the features, but I would really like to know more about the machine if that's even possible. The frame serial plate is there but it is badly worn and I was unable to get the number from a pencil rubbing. I have talked to the local CAT dealer and given then the engine SN (03N18223) but it doesn't show an attached frame serial in SIS. However, I'm not sure if the guy really knew how to look it up, it took him a few minutes. The unit has powershift, a 3306, and is all mechanical (except for the power steering, which i will need to replace some hardline). FWIW, the unit has been sitting in the sun for 6 years and started right up with some new batteries, what an awesome machine. https://imgur.com/a/v9MKWih
I couldn't relate the engine S/N to a machine S/N either. The online links generally work back to the 80's or so. For machines earlier that that they are a bit hit & miss. On the engine S/N plate, does it have an Arrangement Number (e.g. 4N-7377) listed in addition to the engine Serial Number.? Would you like to try taking a close-up photo of the machine S/N plate and post it up.? I can see a couple of possibilities.
Thanks for taking a look, Nige. Here's some up close photos of the frame serial. This is on the RH side towards the front of the main frame, just above the front right wheel. https://imgur.com/a/CNGPzG6
Oops, forgot the last piece of info. the AR on the engine plate is 4N4993
From the S/N plate photo it looks like you have a 10R-prefix 120 grader. The other prefix option is 22R and your photo doesn't seem to indicate that. I'm pretty sure I can make out the "1" & the "0" as the first two digits. According to what I can see the 3306 engine of 03N-prefix was installed in machines from S/N 10R2882-Up. Earlier machines had an 05S-prefix engine with a different Arrgt Number. There are other possibilities not covered in the online system - 13R, 14K, & 70D. It would need someone with paper manuals to help you dive down that rabbit hole but I am reasonably sure those earlier machines all had D333 engines. A machine of that age ought to have the S/N stamped on the machine frame either right next to or even underneath that plate. It may be worth your while to take an abrasive wheel to the paint around the plate. Failing that if you remove the two rivets there is a chance you might find it stamped underneath the plate, or maybe the stamped numbers can be seen better from the back side of the plate than they can from the front.
Awesome data, really appreciate you helping here. I'm going back down tomorrow and I'll see if i can pop the rivets off and/or clean up around there to find the serial stamp. The main reason i'm looking for the serial is so I can narrow down the correct parts book as there are a few small things i need to replace. Again, thanks
Ok, so we found the serial but i think it’s missing a digit… 13U888 with MSO of DUAA153 i’ll attach a picture shortly. looks like it was sold to Darr Equipment in Irving TX originally I have a 13U parts book on the way…
Not necessarily. Back in those days it was custom not to put extra zeros in a Serial Number to make it an 8-digit number. In today's format it would be 13U00888. I don't have access to my S/N book at the moment otherwise I could date it for you. Maybe someone else can assist.
Nige, appreciate it. By no means do I expect anyone to do anything meaningful related to work on the weekend. haha. Just wanted to share what I found. Either way, knowing it’s 13U and that prefix matches with the Arrgt number means i’m good to start ordering parts
It's a 73 according to my book. After #778 it would have come with a 3306 engine. According to my book it is similar to a 10R series, except the book says the 10R has a heavier frame. When I was 23 years old I had the opportunity to operate a 10R grader with about 50 hours on it back in 1974. It was at an iron ore mine in Minnesota. Was doing nothing but road maintaining. It was on a Sunday and regular operator was absent so I got the chance to run a new machine. FWD
So that makes sense with the S/N being 888. As you have found already it's one of the models that is not covered in the online system. So do not count on your local dealer being of too much help when it comes to ordering parts. If they can't find the Serial Number online then to them it might just as well be from Mars..... All three manuals (service, parts, & operation/maintenance) are available on CD or in paper form from - https://www.servicemanualpro.com/?page=Products&searchbox=13U00888
I find that real hard to believe as I've been getting parts for a 61A machine all week and it's a early 60s. as that blade is US scored I bet it's there just have to know how to work Cats part system. Bob
Thanks everyone for the support. I found an original parts book for the 778+ serials on ebay for $40 and picked that up. Need to fix/replace nearly all the hydraulic hoses/pipe. We got everything welded back yesterday, ran it up and down a road here and then the booster line for the brakes (we think?) looks like it blew and dumped a few gallons of hydraulic oil on the road haha. Heading to Cat tomorrow to get them to rebuild the hoses. But again, thanks for the leads y'all!
I had a 60H (Built in Canada I believe?) that wasn't in the computer system, I've walked into Ziegler Cat in Shakopee and the parts guy, with a straight face and a pleasant attitude whipped out the microfiche and found the part numbers I needed and went about his day like it was 1975. That was probably 10 years ago, but Cat was always great about that machine. Volvo on the other hand are a bunch of dinks about a series 4 champion that was built in the late 90's. Thats a good old machine, I put many hours on one of those with a tired D333 in it.
Do you get alot of flat tires on your pickup?
Never on the pickup, that machine on the other hand........... somebody ran calcium chloride in the rims prior to my owning it and it took a few years to get the rims with rust scaling cycled out.
I have worked in a tire shop and alot of people say the grader stirred up the nails.
Could be a local condition, lol.