The Caterpillar D7H crawler tractor was introduced in 1985 as the replacement for the D7G. Production began in Japan a year later.

[edit] Features

The D7H has a 3306 direct injection turbo, six-cylinder engine, producing 215 flywheel horsepower (FWHP). It comes standard with an elevated sprocket, multiple oil cooled clutches and brakes, a sealed and lubricated track, and closed center hydraulics.

[edit] Configurations

It is available in two configurations: the standard model has a track gauge of 78 inches (198 cm), the same as its predecessor; the Low Ground Pressure (LGP) configuration has an 88-inch track gauge, which is two inches (5.1 cm) wider than its predecessor. Both configurations are available with direct drive or powershift transmission. The transmission for a construction application tractor has three forward and three reverse speeds; the agricultural version has six forward and six reverse speeds.

Standard configuration agricultural direct drive tractors were manufactured in the USA, with a 77Z prefix, and in Japan, with a 2SB prefix. LGP configuration agricultural powershift tractors were manufactured only in Japan. They have an 82Z prefix.

Standard configuration, direct drive tractors with three forward and three reverse speeds were manufactured in Japan only, with a 4AB prefix.

Standard configuration, powershift tractors with three forward and three reverse speeds were manufactured in the USA only, with a 79Z prefix.

LGP configuration, powershift tractors with three forward and three reverse speeds were manufactured in the USA, with an 80Z prefix, and in Japan, with a 5WB prefix.

[edit] Modifications

In 1987, Caterpillar introduced differential steering to the D7H model. It released a series of new D7H powershift units with three forward and three reverse speeds in both standard and LGP configuration.

The differential steer configuration units produced in the USA have 5BF prefix; if produced in Japan, they have a 2RG prefix. The newer LGP configuration units produced in the USA have a 4FG prefix, if produced in Japan they have a 3XG prefix. The LGP units came with increased horsepower, 230 FWHP, at the time of their initial release in 1987 and 1988. Standard units did not have their horsepower increased to 230 FWHP until 1993, beginning with 5BF05711 and 2RG05622.

Production of 77Z ended in 1990. The 82Z and 2SB ended in 1991.

In 1990, the Caterpillar D7H Series II was released with new features, including a multiple row module radiator, beginning with 79Z0400, 80Z04000, 2SB04000, 4AB04000, 5WB04000, 4FG04000, 5BF04000, 2RG04000, and 3XG0400. The 4FG, 5BF, 2RG, and 3XG units also received a dual twist tiller control.

In 1992, Caterpillar replaced the fuel gauges, added contour series seats, and improved the cab interior, beginning with 79Z05500, 80Z0550, 4AB05500, 5WB05500, 4FG05500, 5BF05500, 2RG05500, and 3XG05500. All standard configuration tractors (79Z, 4AB, 5BF, and 2RG) had their tracks extended rearward. Meanwhile, the first generation LGP configuration tractors (80Z and 5WB) were given increased horsepower to 230 FWHP.

In 1993, standard configuration tractors had oil cooler capacity increased, and their horsepower was raised to 230 FWHP, beginning with 79Z05623, 4AB05532, 5BF05711, and 2RG05622.

Also in 1993, R134A refrigerant replaced R12 Freon in the air conditioning system for all units, beginning with 79Z05611, 80Z05518, 4AB05533, 5WB05586, 4FG05573, 5BF05690, 2RG05623, and 3XG05515. The 2RG and 4AB units also received increased oil cooler capacity and increased horsepower.

In 1995, Caterpillar made heavy-duty sealed and lubricated tracks the standard for the D7H unit, beginning with 79Z05895, 80Z05524, 4FG05622, and 5BF05955.

Also in 1995, a reduced-emission engine was installed into a number of units, beginning with 79Z05926, 80Z05526, 4FG05632, and 5BF05633.

The Caterpillar D7H was replaced by the Caterpillar D7R.

Production of the D7H ended in 1996.

Based on data from the sales database of Ritchie Bros. Auctioneers, it is estimated that more than 12,900 Caterpillar D7H crawler tractors have been produced.

Highest Serial #

Japan		*04000+	**05500+
2RG	00499	04146	05674
2SB	00896
3XG	00420	04196	05530
4AB	01304	04278	05636
5WB	00802	04187	05507
82Z	00347
USA		*04000+	**05500+
4FG	00381	04151	05550
5BF	00910	04294	06276
77Z	00885
79Z	02368	04375	06015
80Z	00800	04018	05521
Subtotal	9,612	1,645	1,709
Total = 12,966

*When Series II was released Caterpillar jumped the serial numbers to 04000. (Example: 04001 is actually only 1 tractor produced)

**Serial number jumped again to 05500. (Example: 05501 is actually only 1 tractor produced)