Did anyone ever change a 4 speed into a 5 speed?

[notmeu]

I picked up a parts crawler the other day which I believe it is a 1957 JD 420, to have some spare parts on the shelf for my 56’ 420. Going thru most of the parts crawler is the same as mine, which I knew it would be, but except for the transmission which it is a 5 speed. All of the gears are pretty good and I had thoughts of keeping it for parts or incase my tranny falls apart. The question is did anyone ever have any luck replacing a 4 speed with a 5 speed? It appears that the shafts are the same, it’s just a matter of a different shifter and more gears. I guess I’m asking is it worth splitting the crawler to goto a 5 speed?

[Lavoy]

Input shaft is different as well.
Lavoy

[notmeu]

I guess it will go into the for sale parts pile!

[Howard Yoder]

I think it was 2 or 3 green magazines back that the tractor doctor talked about changing a 4 speed to a five speed you may look at that article.
Howard

[440 iron popper]

Hi notmeu

I have 2 440. ''bull 2'' has the early transmission of 440's... so late 420's. Bull 1 has the newer model, different case number but it is the same if you look for bolting it to the reverser case and steering cases. Internal parts are different quite a bit (I compared 420 and 440 transmission internal parts with the part manuals when I opened it) . Both could be swapped (complete assembly for complete assembly). If you don't have a reverser and you have the Bypass shaft, I think you can do anything you want. You could make it shorter or longer to fit your repair. I had a bypass shaft made out of 2 by a machinist. With a good machinist you cannot tell where the join is! So, to answer your question... I would keep it for a swap in case of a major breakdown but I don't think the internal parts will fit from one transmission to the other.