Caterpillar 518/518 Series II Skidder
The 518 was manufactured in the USA, with a 50S or 55U serial number prefix; and in Canada, with a 94U prefix.
The Canadian unit has articulated steering.
In 1972 Caterpillar modified the final drives and made brush guards standard in the 50S unit, beginning with 50S00541.
In 1974 Cat added no spin differentials, beginning with 50S00955. A sleeve metering fuel system was also added, beginning with 50S01028 and 55U00235. The hitch was modified on the 55U unit, beginning with 55U00263.
In 1975 the brush guards were modified, beginning with 55U00316.
In 1977 Cat added a fuel system water separator, beginning with 50S01969 and 55U00413. At the same time the 55U unit had its horsepower increased to 130 FWHP.
In 1978 the winch arrangement was standardized, beginning with 94U00526.
In 1979 a water separator was made standard on the Canadian unit, beginning with 94U00522.
In 1980 and 1981 the U-joint was modified on American units, beginning with 50S03449 and 55U00658; they also received 3304 direct injection engines, beginning with 50S03229 and 55U00669. At the same time Cat added grapple controls and extended the wheelbase on the 55U unit. All units had their ROPS modified, beginning with 50S03229, 55U00669, and 94U00691. Cat also added a sleeve metering fuel system to the 50S and 94U units at that time.
In 1981 Caterpillar introduced a new 518 unit in Canada, with a 95U prefix. It comes standard with a 3304 direct injection, turbocharged engine producing 130 FWHP. It also has a sleeve metering fuel system, grapple controls, extended wheelbase, and modified ROPS.
Production of 50S and 55U ended in 1983.
In 1983 Cat added a scroll metering fuel system, beginning with 94U00741 and 95U00154. The torque converter was modified, beginning with 94U00774 and 95U00356.
Larger final drives were added the 94U unit in 1984, beginning with 94U00946.
In 1985 a Cat 518 winch was added, beginning with 94U01298 and 95U01184. At the same time the 94U had its horsepower increased and its wheelbase extended.
In 1986 Caterpillar introduced a new 518 unit in Canada, with an 8ZC prefix. It comes standard with direct electric start and a feller buncher arrangement.
Production of 8ZC ended in 1989.
The Cat winch was modified in 1990, beginning with 94U02334 and 95U02887.
Caterpillar introduced 518 Series II in 1991. It consisted of modified 94U and 95U units, beginning with 94U02504 and 95U03205. It featured 130/145 dual FWHP rating.
Production of 518 ended in 1992.
Based on data from the sales database of Ritchie Bros. Auctioneers, it is estimated that more than 10,900 Caterpillar 518/518 Series II skidders have been produced.
|Total = 10,915|