Information About 1979 4X4 Chevy Transfer Casesby Steve Hamilton
There were two transfer cases available on Chevy trucks in 1979. New Process made both gear boxes. Although first introduced in the early 1970s, the strength and durability of these gear boxes make them popular with off-road enthusiasts in 2011.
The NP203 is a full-time, four-wheel drive transfer-case. There are two high and two low gear-selector positions, plus neutral. The gear ratios are 2.01-to-1 in low and 1-to-1 in high. When in high or low lock, the transfer case differential turns the front and rear axles at the same speed. The NP203 is chain driven.
The NP205 is a part-time, four-wheel-drive transfer case. There are three gear-selector positions, plus neutral. Four-wheel-drive is available in a low range of 1.96-to-1 and a high range of 1-to-1. Two-wheel drive is high-range only; the front drive shaft does not rotate in the high range. The NP205 is gear-driven.
Although both transfer cases are stout, the NP205 is the favorite of serious off-road enthusiasts and Chevy aficionados; this is because of its gear drive and cast-iron case. The NP205 has a slight edge in fuel mileage and component wear, because it was designed as a true, part-time four-wheel gear box. Aftermarket kits to convert NP203 equipped vehicles to part-time operation are available.
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