The Caterpillar D8 is a large track-type tractor designed and manufactured by Caterpillar. Though it comes in many configurations, it is usually sold as a bulldozer equipped with a detachable large blade and a rear ripper attachment.
1935: RD8 introduced.
1937: The "R" prefix dropped, D8 debuts.
1940s: 2U Series D8 introduced; engine power of 132 hp improved to 148 hp.
1950: D8 new front-rounded grill that would last until D8K was replaced by D8L in 1982.
1955: 1H Series D8 ends production; 191 hp D8E and D8D introduced with new 1,246 cubic inch displacement (CID) D342 diesel engine. D8D had a torque converter and D8E had a direct drive transmission.
1956: D8D replaced by D8G.
1956: D8E replaced by D8F.
1958: 235 hp D8H introduced.
1965: Power increased to 270 hp
1970: D8 46a 48a power increased 280 hp
1974: 300 hp D8K replaced the D8H.
1982: 335 hp D8L replaced D8K. The D8L was the first D8 with the elevated drive sprocket undercarriage.
1984: D8L SA (special application) for farming applications premiers. Available with a Three point hitch, for mounted implements.
1987: D8N at 285 hp which was unveiled at CONEXPO '87 in Las Vegas. It also had a differential steer transmission — the first track-type Caterpillar tractor to have one.
1996: 305 hp D8R replaced D8N.
2000: D8R Series 2 replaced the D8R.
2004: 310 hp D8T ACERT replaced D8R Series 2.
Several types of bulldozer blade can be used on the front of the tractor:
straight blade ("S-Blade"): A short blade with no lateral curve and no side wings. It can be used for fine grading
angle blade: held by an U shape frame that has three holes on each side, to set the blade to 3 positions: right, center, and left.
universal blade ("U-Blade"): A tall and very curved blade with large side wings to carry more material
"S-U" combination blade: A shorter blade with less curvature and smaller side wings
People use various other blade types, including landfill U-Blades, woodchip U-blades, and two-way blades for work inside the holds of ships.
