The Cat FORTY

Series 5G1-5G584, 1934 - 1936

The Gas FORTY replaced the (gas) THIRTY FIVE in 1934. It had a slight increase in power from 38 D.H.P (Drawbar Horse Power) to 44 D.H.P.

Like most tractors of the period, the FORTY was made in two versions, narrow 56 inch (see below) and wide 74 inch gauge versions.

The track frames were now welded rather than riveted. The FORTY was made in small numbers as diesel tractors were becoming more popular.

Cat FORTY

Photograph courtesy of Galynn Ferris

Production began in 1934 and continued until 1936 with only 584 tractors being built.

FORTY Details

5G1-5G584
1934-1936
4000G Spark ignition Engine 4 cylinders 5 1/8inch x 6 1/2inch bore / stroke.
44.19 D.H.P.
Weight 13,140 lbs.

Below is a list of machines made by year and serial number.

Year	5G
1934	1	42
1935	43	433
1936	434	584

Created by John Gaunt

The members here at ACMOC have a wealth of knowledge on Caterpillar machines and machinery.

Join today and you'll find digitized original manuals, historical photos, helpful members, and a wealth of information whether you already have a Caterpillar machine or are thinking of getting one, like the rest of us here at ACMOC, and trust us, you do need one.

The ACMOC Members Library contains Operation and Maintenance Instructions books, Parts Catalogs and Serviceman’s Reference Manuals, as well as links to YouTube videos showing detailed restoration of many popular tractors and some less popular ones!

Follow Us on Social Media

Our channel highlights machines from the earliest Holt and Best track-type tractors, equipment from the start of Caterpillar in 1925, up to units built in the mid-1960s.