Early John Deere Engines and Running Gear

[Canuck 420c]

Hi folks,
I have a question in regards to the engines and running gear on early John Deere crawlers and wheeled tractors M,40,420 ect.... what was the mechanical differences between each series up to the 440? as i have seen later JD ads stating the "New John Deere Engine" in the ads.I aways thought that the engines and running gear were pretty much the same from the MC onward wich was the same for other early two cylinder John Deere tractors

[Stan Disbrow]

Hi,

Early ones were a bit smaller displacement in the M and 40. Later ones were a little larger in the 420. 430 and 440. You can tell by the water pump the larger ones have and the smaller ones do not.

Transmissions were originally 4-speed and later 5-speed. Then came the gear reverser and, later, the differential one.

If you sit down and read thru the parts catalog, you can see where this was all a series of running changes within each model number or letter. There never was a really good break from X to Y in most things until the JD350 came along to supplant the 1010. Then, I think they reused about four bolts total....

Stan

[Lavoy]

Yes and no. M and 40 were same displacement, 40 has bigger rod bearings, aluminum pistons, fan shround, and spins faster. 420, 430, 440 were all same displacement, 430/440 blocks were different because of RH side dipstick. Late 440 gas was higher compression, different head, small carb change, and spins faster. Many, many transmission changes, final drive changes, gearing changes, etc throughout the years, and things were just built different between the models, options that were introduced on later crawlers, as well as running changes that would be serial number specific to the model in question. There is no real easy answer.
Lavoy

[Canuck 420c]

Thanks for the help gentleman

This is the ad from 1956 that has me asking this question

[Stan Disbrow]

Hi,

The '20' in all the new 3-digit model numbers signified a 20% increase in engine power from the predecessor 2-digit model numbers (i.e 420 v 40, 520 v 50, etc)

In this case, an increase that meant they now needed a water pump for cooling.

Note that a power increase doesn't hold for the 430 which followed the 420. That was a styling change.

Stan