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What is the serial number on my D6C Cat?

Keith K · 2024-11-24 20:47

I'm working on my brother's 60's or 70's vintage D6C dozer. I've found two different serial numbers on it. The number on the back is covered by a winch if it's even there. The number on the block is 70B2069. I didn't find a tag on the dash, but I found a tag on the hydraulic tank behind the dash. That number is 39F4372. I haven't found a service manuel or parts catalog associated with a 70B or 39F series or, for that matter, any reference to these series. Are these numbers legitimate? I used to own a D6B series 44A and a D6B 37A series and did a good deal of work on both of them. This D6C looks a lot like the D6B's that I'm familiar with. The machine I'm working on now has a decal that reads D6C that looks legitimate.

Replies13
  1. #1pittsburgh cat man2024-11-24 22:14

    70b is engine serial 39f is a 163 hyd control Some one with sis might be able to tell you what those serial number are on. I'd guess about a 10k tractor serial number

  2. #2Keith K2024-11-24 22:28

    That's good to know. Thanks. I'll check with a local dealer tomorrow.

  3. #3.RC.2024-11-25 04:10

    The engine is not original. 70B is a S/N for a 1673 truck engine. CATERPILLAR CAT 1673 ENGINE SERVICE MANUAL S/N 70B | eBay Find many great new & used options and get the best deals for CATERPILLAR CAT 1673 ENGINE SERVICE MANUAL S/N 70B at the best online prices at eBay! Free shipping for many products! www.ebay.com

  4. #4Nige2024-11-25 04:35

    We have a saying where I come from - "just because our local buses carry ads on the side for washing powder it doesn't mean they take in laundry". The decals may be correct for the period but it certainly wouldn't be the first machine to which someone has given a DuPont overhaul and re-stickered to make it look like something it wasn't. To be honest without removing the winch and checking for a stamped machine Serial Number on the LH corner of the rear case the best way to track it down might the the 39F Serial Number of the Hydraulic Control. The dealer probably will not be able to do that, they would have to ask Cat to track it down from the factory build records. 39F production started in 1959 but with a Serial Number in the 4000's on your machine that would probably make it somewhere early-to-mid 60s I would guess.

  5. #5Mcrafty12024-11-25 05:57

    A picture of the overall machine from a few different angles may make determining roughly what vintage it is, some structural changes were made through the years of the D6C.

  6. #6Keith K2024-12-07 18:39

    The dealer couldn't trace the serial number. It's too old to be in the SIS. When I bought parts for the track tensioner, the parts that fit came from the catalog for a D5 26X. The undercarriage appears to be for a D5. Apparently, some of the D6 9U's had the same undercarriage as a D5, so I'm thinking that it is a D6 9U. I looked behind the winch. There is a space about two inches between the winch and the back plate on the cat. I didn't see anything that looked like a tag for the serial number. My guess is that it's a higher rather than lower serial number in the 9U series. Anyone recognize it?

  7. #7pittsburgh cat man2024-12-07 18:52

    check top left of rear of frame usally stamped under where the tag was

  8. #8Keith K2024-12-07 18:55

    I'll try to clean it up and see if the number is stamped into the frame itself.

  9. #9Nige2024-12-07 19:00

    I could have told you that before you went there. It's no good going to the parts counter with a challenge like this one. As I mentioned earlier the best way for the dealer to find the machine Serial Number would be for their Technical Communicator to contact the factory with the 39F4372 Serial Number from the hydraulic control and ask them to look in the records for the machine Serial Number that control was installed on when it left the production line. Records will exist, it's just a case of someone getting off their *** and looking.......

  10. #10Old Magnet2024-12-07 19:25

    39Fxxxx is a 50 gpm single valve 163 Hydraulic Control used on early D6B 37A and 44A

  11. #11Darwin092024-12-07 21:15

    Dozer looks like a D6B to me,

  12. #12bccat2024-12-07 23:00

    It’s a D6B,

  13. #13Rusted2024-12-08 00:21

    6B for sure.