CAT D4D 78A serial # question...

[Shop Dweller]

I aquired an old 78A D4D Caterpillar dozer that was about ready for the junkyard, that I have brought back to life. There are some numbers stamped below the serial plate on the engine. The serial plate itself reads 78A4087. My confusion comes from the fact that Carolina Cat says that Cat says this serial number never existed. My computer confirms that when on Cats website. Although I know Carolina Cat has more access than me. Could the numbers stamped below indicate a serial number correction? I have asked a few people who know these 60s dozers well, and they don't know. The stamped numbers would make it 78A4217. And it may not even be the original engine, because it has a winch and I have never seen the rear serial number. I have all the manuals for this machine and a few things are off. Example, the plate on the hydraulic tank doesn't seem to match these dozers but the valve body does. And I am pretty sure the C-frame isn't what it would have came with, but the number isn't totally out of the range of possibility. It's not a huge deal until you are trying to order parts that changed during 78A. Any help appreciated! I will attach a picture of the serial plate and stamped numbers, as well as pic of tractor when I got it and now. Thanks ya'll!

 

[Nige]

The serial plate itself reads 78A4087. My confusion comes from the fact that Carolina Cat says that Cat says this serial number never existed. My computer confirms that when on Cats website.

With a machine that old the "as built" configurations disappeared from the online system quite a while ago. The "Warning: No Product Configuration data to display" message doesn't mean that the machine never existed, it means Cat lost the info about it somewhere in the last 60 or so years..........

I wouldn't mind betting that if they asked the factory the info might just be available somewhere in the archives.



Are they using 78A4087 or 78A04087, the latter of the two would correspond to the latest style of 8-character Serial Numbers. Back in the day Cat never put zeros on plates between the prefix (78A) and the S/No.

I can't explain the "4217" stamped below the engine S/N plate. Maybe someone else can. In the absence of information to the contrary I would go with the number on the plate rather than the stamped one below it although at the end of the day it might make no difference as the two numbers are so close together.

EDIT: @Old Magnet was posting while I was typing.

 

[Old Magnet]

Both s/n's are good and both are same 1965 production.
Just to old for the SIS.
Many parts from D4D's and E's would interchange.

 

[Nige]

the plate on the hydraulic tank doesn't seem to match these dozers but the valve body does.

What's the Serial Number of the Hydraulic Control.?

 

[Shop Dweller]

I will get back to you on that one. It seemed to match the 43? I think it was? Single valve pretty close, but I never could match it exactly. But the control valve number did match. Or maybe the other way around. When im back around it I will gather that info.
I have a 64' 6C that has made the scrap heap, roller frame had been broken, and repaired so many times it was "bow legged". And the engine was in need of overhaul, so I upgraded to a late model 6D. But in Charlotte, when it was still Carolina Tractor, they could pull that C up. But thats been 10 or 11 years ago. I can't remember it's serial right off. I miss that machine, it was a turbo straight drive beast. I shelled many a final drive...lol. But what got me thinking about miss print serials, is that I had a D6M that actually was stamped with the wrong number in the cab. Two numbers were transposed. Funny thing is, the people at Cat think that number for the D4D should be in the system, so I believed them. Thanks I will get back on the hydraulic system group.

Oh btw... it has a decomp in the head, but has no sign of ever having a pony. And it's 24v. Is that strange or did they all have the decomp? According to my parts book some did not.

I thought those numbers would be a mystery under the plate. Because D6Merv has been a huge help, but he didn't know what they were.

 

[Nige]

But in Charlotte, when it was still Carolina Tractor, they could pull that C up. But thats been 10 or 11 years ago.

That was before SIS changed from v1.0 to v2.0 about 5 years ago. A lot of information disappeared into a black hole when that "upgrade" happened and has been AWOL ever since.

Funny thing is, the people at Cat think that number for the D4D should be in the system, so I believed them.

Sorry but they are wrong. I've never found anything recently for machines earlier than the mid-to-late 70's

 

[Shop Dweller]

Trust me. I believe you more than them. I think they would walk into walls without a computer. I remember when the big store in Charlotte fitst went to computers my dad would tell them you are gonna have to quit poking that thing and dust one of them books off if, you know what a book is... thats been over 30 years ago, hard to believe. No wonder we get old.

 

[Mcrafty1]

My D6C was long absent from SIS, but Cat had Legacy books that would tell them everything they needed to know to get parts. Don't know if that helps in your case but it sure did in mine...after I found that out and mentioned it to Cat...presto! it was like a light went on at their parts desk. For what ever reason no one present at the time knew anything about the Legacy aspect of Cat.

My D6C was the 76A vintage....A 1967 Build if I recall.

 

[Shop Dweller]

In Charlotte which is 1.5 hours away they have all that older stuff, and maybe in Greensboro, but not out in the branches that im close to like Boone, NC.
BTW.... my 6C is a 76A. They were built only from 63 to 65 Im fairly sure..
Don't be shocked because I thought mine was a 69' for years...lol.

 

[Old Magnet]

76A D6C's were built from 1963 to 1967 total 6061 units built.

 

[Shop Dweller]

76A D6C's were built from 1963 to 1967 total 6061 units built.

You are probably more correct than I am. I have been told many times that the 83 S/N started in 1966. Thats how I first found out that mine is older than 1969. I assumed after being told that several times it were true, I guess not. I am going to visit my old 6C here before long and rob it of it's 24v alternator for use on my D4D. I will refresh my memory on the serial number exactly. Would be interesting to know the exact year for 100% sure. Anyone needing parts for one of them let me know. I have mainly only robbed it of undercarriage stuff for my 6D. It was a running machine when I parked it, Straight drive, turbo, angle blade, manual tilts. Engine was tired, I built the engine in 1995 and ran it till 2014. Actually built it with much help from my dad, I was only 20 and it was my first deep dive into a diesel engine. We had another one I got to build twice thanks to either. Stay away from glow plugged Cats with either. But anyway, the rest was good pretty much, all but the roller frame was squatted/sprawled it had been broken so many times. Its in NW North Carolina. Near Boone.

 

[Shop Dweller]

What's the Serial Number of the Hydraulic Control.?

So here is one thing I found "off" with the S/N...
I have an older series C-frame. Which could have been an easy switch in the past. I am still trying to remember what was off about the hydraulic group. I may have been looking at the wrong page in my hydraulic control book.

But the C-frame I have seems to be from an earlier model, because I have the one in the attached picture.

 

[Shop Dweller]

76A D6C's were built from 1963 to 1967 total 6061 units built.

I had an old man moment for a moment.... my ol' 6C was a 74A ...
I guess I had 76 in my head because I was born in 76 I guess....lol.
I visited ol' girl today. My dad bought her in 1972 with less than 1,000 hours. Thats back when all the loggers just had 450 John Deere dozers and stuff like that. I have had old timers tell me that my dad was legendary for being a logger with a dozer like that back then. It ended up being mine and wasn't retired till 2014. It had been ran so much that the lower final drive housings were worn through and leaking straight through the steel. That thing has punched out many a mountainside logging road. She isn't looking to proud these days, but it's good to see her again. My dad put me on this machine at 7 years old and drove away while I cleared river bottom for my grandfather. I was just making a mess, but thats life lessons kids don't get these days, not even close. There have been times when I could have scrapped her for 6 or 7 thousand, but I can't do it, nostalgia I guess.

Could you give me the true year model? I think I know, but not 100%
S/N 74A 0948

 

[Old Magnet]

That's a 1964 model.

 

[Shop Dweller]

Well I was right for once....lol