1959 641D Serial Identification and Restoral

2 years ago, my buddy gave me a 1959 641D tractor out of his field. Most of the tractor was in fair shape, short the baseball-sized hole in the block from a rogue push rod and missing heads. When i got it, i did some research on different options to re-power it and bring it back to life...but none of them were economically feasible.

Yesterday, I bought a second 641D that is completely original (complete motor, fenders, lights, etc) for $800. It has been a few years since the tractor has started, but the owner claims that it should start right up if I fix the injector pump which is not allowing fuel to the cylinders (we'll see..LOL) I plan to use the first as a parts tractor (if needed) to restore the one i just bought.

My first question is regarding the serial number:

Per other posts on this site, I looked above the starter, below the battery box. I looks like all the numbers are eroded away. Is there any other location of the serial number for this tractor? What are my options?

Here is a picture of the tractor i bought from a previous subscriber on this board. I have reviewed some of the threads to questions he posted 6-8 months ago. I am picking up where he left off.

My 641D has the same problem in the serial number area, and from what I have read on this board, it is the norm for the diesels. Apparently over the years, battery acid leaks on the pad where the serial number should be and erodes it. Ford did not have a better idea in that piece of engineering.

It is possible that by careful sanding and polishing of the pad, you might be able to see the serial number and model number, as the metal under the surface may have been disturbed when the numbers were originally stamped. It also might help make the characters visible by putting a little hydrochloric acid on the area after it is smoothed and polished. It might work and it might not.

On the other hand, knowing the correct serial number is not that important, at least to me. I know by looking at it that my 641D is that model, and from details, I would guess it was built in about 1960. And since the serial number is on the transmission casting, one could only ASSUME that the transmission in the tractor today is the same one it left the factory with.

In my state, it is illegal to restamp a serial number, and machines that have been restamped can be considered contraband, and can be seized by police if they happen to come across the fact that something is restamped. I wouldn't do it!

A worse problem that you have is that parts for the 144D engine you have are hard or impossible to come by. The block, pistons, connecting rods and some other parts are different for 144's than similar parts for the 172D engines. I looked all over the internet for a 144 rebuild kit, but never found any. So I bought a 172D engine that may be usable as is, or if necessary, I will rebuild it with an easily available 172 kit. It appears that many fewer 144's were made than 172's, and the aftermarket chose to only support the 172.

Unless the engine from the second tractor can be made to run OK, I think you will come to the same conclusion I did: that it didn't make sense to try to rebuild a 144. 172D engines are out there and rebuilds are doable, if kind of expensive. Some of the parts from the destroyed 144 engine might be usable, if not exactly correct for a 172, depending on how much damage the broken parts made. The cranks were the same for both engines (or was it a connecting rod that put the hole in the block? I was trying to visualize how a pushrod could break a block). I bet a 144 head would work on a 172, as would the camshaft and most external parts. The injector pump would probably work on the larger engine, although if I had a choice, I would use the correct pump.

The added power of the 172 could be hard on the 601 series rear end. The 601 had a rear end that was smaller and presumably less robust that the 8xx rear end. But it would probably work fine.

My old 641D keeps on running--it starts fine and has decent power. But the oil pressure is not very good anymore and it uses and loses quite a bit of engine oil. It probably has a lot more than 10K hours on it. I may try rolling in new bearings to try to raise the oil pressure, but probably I will end up installing the 172 engine I bought several years ago. With any luck, I will be able to get that engine to work for me.

Good luck with your tractors. I have had lots of fun with mine. Hope this helps.

What parts are not available Hal?
I'm sure that my friend Kenny had a 641D engine rebuilt about a year ago.
Dunno what all was done but I assume bore and pistons at least. I don't know what was done to the crank.
At the time I remembered hearing about 144 parts being mostly NLA and was a bit surprised that it was done.
I'm pretty sure either here on this board or maybe talking to the rebuilder I heard those engine parts were made in Italy, used in other applications and still available.
I didn't follow that particular engine. But I did help put it back into the tractor. I doubt it was an empty long block.
I could ask about it if someone was interested.

All of the major castings (head, block, trans, rear end center section, axle trumpets and lift cover) have a casting date code cast into them. These will be 3 character combinations of letters and numerals and the first character should be the numeral 8 or 9 if your 641D is in fact a 1959 model.

Look at the pictures in the link and tell us what #'s you find and where you found them. If a letter is upside down we need to know that.
date code pictures

Thank you for your reply. I will be back at the house this weekend and will post a picture of my "parts tractor" with the hole in the block. I am wondering if the injector pump from the parts tractor could still be good, even though it has been sitting for a number of years. The seller of my second tractor seems to believe that the injection pump is what is preveting it from running.

That's great info! Thanks! I will be sure to look at all of those numbers and see what I come up with. Thanks for the answer.

John,

i looked all over the place to find that .jpg from the ford tractor manual that gave production months by serial numbers. I found that one time when I got my first 641 that has a legible serial number. I was pleased to see that as part of your link. I'll dig on these other numbers this weekend and post what i find.

thanks!

Is there a good checklist out there for someone looking to start up a tractor that has been sitting for several years? It seems like there would be some wisdom in the do's/don'ts and "make sures" prior to starting it up.

thanks!

The Date code on the right side of transmission reads 91G right below the number 310835

The date code under the seat looks to read 91J

The date code on the engine (left side of block) looks to read 88*T 1

The serial number is completely gone.

Does this validate that it is indeed a 1959?

Here is the block picture from my 641D Parts tractor. I won't be rebuilding this one!


The model and serial number off of my parts tractor reads 641 and 67391. This means it was built in Feb of 1959. I thought that the 641 would also be followed by a D or symbol for diesel...but it isn't. Is that strange?