The 140 was in production from 1968 through 1974. Along the way many changes, some significant and obvious, others less so, were made. Almost every year, something was improved on them, and the cumulative effect of the big improvements/changes settled in by 1972 on the H-3 models. So any model H3 1972 or later, and H1 1973 or later, has most of the beneficial changes that were made.
That is not to say the pre-72 tractors are bad. Definitely not. They are also great trators! It's just that the "goodies" that really improved the platform are all in place by '72. However, there is a caveat: A 1972 H1 actually is somewhat less desirable in many respects to earlier and later H1s. More later.
Some highlights of important changes made:
-1968, first year of production, 12 hp engine, no steering brakes
- 1969, engine hp was increased to 14 hp from 12 hp
- 1969, true "H3" was added (as opposed to a splitter to create three spools from two spools)
- 1969, steering brakes were added
- 1971, new hydrostatic transmission was sourced (previous transmission is much harder to find parts)
- 1971, beefier rear axle
- 1971, change from disc brakes to more reliable drum brakes
- 1972, "engine disconnect" feature dropped from H1 models
- 1972, change from 3/4" to beefier 1" front axle spindles for more load carrying capability
- 1972, front wheel bearings changed to cassette style, making it easier to remove front wheels
- 1972, new rear axles and hubs to accomodate switch to inboard seals on the rear axle seals (changed from outboard style)
- 1972, watered-down H1 version lacking steering brakes, 3PH capability, no rear hydro ports option, etc (the 1972 H1 models were very similar to the short-lived Model 120, just with a 14 hp engine.)
-1973, "engine disconnect" feature dropped from H3 models (engine disconnect allowed the shaft driving the transmission to be disconnected from the engine, by depressing the left pedal. In this way, the engine can be run without powering the transmission.)
- 1973 H1 returns to "normal" and has same features as H3, only with single-spool hydraulics
- 1974 last year of production H1/H3