Compare/Allis Chalmers B vs Allis Chalmers U

Allis Chalmers B vs Allis Chalmers U

Verdict: Allis Chalmers B vs Allis Chalmers U

The Allis Chalmers B and the Allis Chalmers U are both tractors — here is how they stack up on the figures that matter. Both are rated at the same 20 hp. Allis Chalmers B is the lighter machine (934 kg vs 2,086 kg), which helps on soft ground and transport, while the heavier model carries more ballast for traction-limited draft work. Allis Chalmers U holds more fuel (90.8 L vs 45.4 L) for longer stints between fills. Allis Chalmers B is the newer design (1938 vs 1929). Use the full side-by-side spec tables below to weigh the details against your own operation, and confirm with a dealer demo.

Tune the fit score

Tell us about your operation

Acreage600 acBudgetMain crop / use

Fit & specs

Allis Chalmers

Fit score

Best match

Clear

Allis Chalmers

Fit score

Best match

Clear

Rated power

20 hp

Confidence

40%

Guide price

—

Overview

Manufacturer

Allis ChalmersReference

Gear 1 used for pull test.Reference

The four-speed transmission was offered on tractors equipped with rubber tires.Reference

Factories

Southampton, EnglandReference

—

Total built

120,783Reference

19,009Reference

Steering

manualReference

—

Variants

industrial tractorReference

—

standardReference

—

row-cropReference

Engine

Fuel tank

45.4 LReference

90.8 LReference

Plows

1 (16-inch)Reference

3 (14-inch)Reference

Drawbar (tested)

14.5 kWReference

22.6 kWReference

Belt (tested)

16.6 kWReference

26.1 kWReference

Displacement

1.9 LReference

5.2 LReference

Bore/Stroke

76 x 102 mmReference

114 x 127 mmReference

Air cleaner

oil bathReference

—

Compression

4.92:1Reference

—

Rated RPM

1400Reference

1200Reference

Firing order

1-2-4-3Reference

—

Starter volts

6Reference

—

Oil capacity

5.7 LReference

—

Sparkplug

AC 45Reference

—

Sparkplug gap

1.016 mmReference

—

Point gap

0.508 mmReference

—

Intake valve clearance

0.254 mmReference

—

Exhaust valve clearance

0.254 mmReference

—

Coolant capacity

7.6 LReference

18.9 LReference

Belt power (max)

16.6 kWReference

25.4 kWReference

Max power

14.5 kWReference

22.6 kWReference

Drawbar (claimed)

—

14.9 kWReference

Belt (claimed)

—

23.1 kWReference

Transmission

Gears

3 forward and 1 reverseReference

4 forward and 1 reverseReference

Clutch

dry discReference

—

Oil type

[0oC]Reference

—

32oF [0oC]↑

: SAE140Reference

—

32oF [0oC]↓

: SAE90Reference

—

PTO & Hydraulics

Type

unsynchronized gearReference

—

Rear PTO

transmissionReference

—

Rear PTO Type

560Reference

—

Dimensions

Wheelbase

186 cmReference

—

Weight

934 kgReference

2086 kgReference

Front tire

4.00-15Reference

28x6Reference

Rear tire

9-24Reference

42x11Reference

Ag front

4.00-15Reference

6.00x16Reference

Ag rear

8-38 (Asparagus Special)Reference

12.75x24Reference

Length

280 cmReference

300 cmReference

Height (exhaust)

194 cmReference

—

Shipping weight

934 kgReference

—

Ballasted weight

1901 kgReference

—

Ground clearance

71 cmReference

—

Front tread

96 to 152 cmReference

—

Rear tread

101 to 152 cmReference

—

Height

—

135 cmReference

B Serial Number Location

B Serial Numbers

1938

97Reference

14855Reference

1939

11800Reference

15587Reference

1940

33502Reference

16078Reference

1941

49721Reference

16722Reference

1942

56782Reference

17137Reference

1943

64501Reference

17470Reference

1944

65502Reference

17802Reference

1945

70210Reference

-unknown-Reference

1946

1001 (IB)Reference

-unknown-Reference

1947

1003 (IB)Reference

18309, 20174Reference

1948

1010 (IB)Reference

18613, 20179, 21000Reference

1949

1282 (IB)Reference

20301, 210036, 22018Reference

1950

1556 (IB)Reference

20422, 22024Reference

1951

4001 (EB)Reference

—

1952

6861 (EB)Reference

—

1953

9200 (EB)Reference

—

1954

11120 (EB)Reference

—

1955

124711Reference

—

1956

126497Reference

—

1957

127186Reference

—

Final

127461Reference

—

Capacities

Diameter

20 cmReference

—

Width

157 cmReference

160 cmReference

RPM

1053Reference

—

Electrical

Ground

positiveReference

—

Charging system

generatorReference

—

Charging amps

12Reference

—

Battery volts

6Reference

—

Test results

Belt fuel use (max)

7.9 l/hourReference

15.5 l/hourReference

Max pull

1209 kgReference

1112 kgReference

U Serial Numbers

1929

—

1Reference

1930

—

1975Reference

1931

—

6554Reference

1932

—

7262Reference

1933

—

7419Reference

1934

—

7685Reference

1935

—

8063Reference

1936

—

9471Reference

1937

—

12822Reference

Location:

—

Rear of differential, near PTOReference

Fit score weighs budget, operation size, crop match and data confidence against the details above. It’s guidance, not advice — always confirm with a dealer demo.