In general, the only way to differentiate
one year Model B from the next is by looking at the serial number.
The following chart lists many of the the major parts changes that were made
during the course of Model B production.
A few of these DO correspond to the change in the model year.
These changes can be used as a guide in determining the approximate year
of your tractor if the serial number plate is missing.|
The chart can also be used to determine if someone has replaced parts on your tractor with later ones that don't belong on a tractor with that serial number - or "retro-fitted" it, so to speak.
Notice that the two uses of the chart may be mutually exclusive. If you don't have a serial number, and someone has used parts that don't belong on that year, you are out of luck! And I won't even attempt to list the changes in wheel equipment; entire wheels are often swapped, just to get better tires!
This is certainly not all of even the major parts changes that took place. More will be added to this list as they are discovered. Minor changes may be added too.
|Year||Serial Number||Changes in major parts at serial #:|
|1935||1000||1509 Last fuel-filler on centerline of tractor|
3043 Last 4 bolt front pedestal
11506 Rear axles lengthened
|1936||12012||12743 First factory installed heat gauge|
|1937||27389||29631 New front hubs available,|
to accept pressed steel wheels.
34951 Last curtain radiator shutter
42133 Last loop drawbar
42133 Last short frame
42200 First long frame
|1938||46175||58246 Last 1938 B|
|1939||60000||60000 Tractor becomes styled|
60000 Tractors with starter have slant dash
63479 Last aircleaner with two wingnuts
|1940||81000||82447 PTO guard is redesigned|
|1941||96000||96000 Major engine change|
6-speed transmission begins
Tractors with starter have straight dash
|1943||136315||136662 Wartime cast iron frame starts|
148500 Pressurized cooling system begins
|1944||149219||149699 Last 2 piece sliding drawbar|
149700 First 1 3/8 dia. PTO shaft
|1945||167700||167000 Angle-iron frame begins again|
167000 Last breather with short flat stack
167000 Copper radiator core returns (unpressurized)
167010 First breather with mushroom cap
171992 Fan assembly redesigned
|1946||179788||186133 Last oldstyle drawbar frame|
|1947||191303||201000 Major redesign|
Larger engine with 4 11/16 bore
First pressed steel frame
First padded seat with battery box
|1949||230044||232468 Brake drum now unbolts from the outside|
|1950||253025||259525 Second plug added to Reduction Gear Cover|
260518 Gearshift quadrant changes to two-piece
260984 First square rear axle housing
268820 Distributer becomes standard equipment
|1952||293030||306600 First water pump|