955 12a, new to me

Check that tractor serial # again. I show production only going to 12A8418. The 9Sxxxx is a late D315 Industrial engine so somewhere along the line the engine has been changed.

Yes, carb gaskets and parts are still available from Cat and aftermarket.
The carb is a Zenith model TU4C and is also shared with John Deere pony motor.

I'll check tonight, maybe I have an extra 0, how about 12A1540.

I see some delineation in the different parts manuals. Are there many major differences between my pre 9S11730 and post 9S11730? Looks like another delineation at 9S5001 and up, my 9S11497 must be covered in this group.

Ok, thanks. Local Cat dealer referenced me to go to a local aftermarket shop.

1540 would work and be a 1956 model. Yes, you are in the 9S5001-up series and that is the beginning production number for the 9S series.

My listing info for the 9S tops out at 9400(1953) but the series went on to 1959.

What is the preferred method to repair method for the threads in the float body? :doh:
I saw a thread around here somewhere, one said over size drill and tap, one said helicoil, I was thinking fill with JB weld or other suitable epoxy, then redrill and tap to stock 1/4-20. What about plug weld in aluminum and redrill and tap? Maybe best case, find a good used one....

Thoughts? 🤓

1540 would work and be a 1956 model. Yes, you are in the 9S5001-up series and that is the beginning production number for the 9S series.

My listing info for the 9S tops out at 9400(1953) but the series went on to 1959.

I verifed the serial number last night and few other numbers as well, wondering what they all mean.
SN 12A5400, Is this still 1956?
Trans group 4H9950
Mag PN MJK4/2360C-47
Mag SN 3A366468
Zenith Carb 5F3527 10368C

How can I tell what D4 series tractor? The Serv Ref Book I have lists 4G, 7J, 2T, 5T, 6U and 7U.

The D315 engine was used on "U" model D4 tractors. The 955 is based on the 7U (wide gauge) D4, the 6U is narrow gauge.

Your new serial number is a 1958 model.

The rest of those numbers are normal for the model.

For those wiped out threads in the bowl, I wouldn't use epoxy at all due to heat and fuel possibly softening it. I'd go ahead and heli-coil those threads. .if you don't want to buy a kit, most machine shops have 'em and can do the job for you. As far as plug welding the holes, I agree with OM. .don't!