New Process NP203

NP203 Transfer Case Specs & Ratios

The NP203 chain drive transfer case was used in 1974 to 1979 model year Dodge/Ford pickups and 1973 to 1979 model year GMC/Chevrolet pickups. Its biggest downfall is that the transfer case came from the factory as a full time unit. An internal differential is used to split power between the front and rear axles in similar fashion to how an open axle differential distributes power between the left and right tires.

The transfer case can be converted to part time operation, a common modification to eliminate many reliability concerns that arose from the transfer case operating at all times. Additionally, a part time conversion reduces drag and can noticeably increase fuel economy in NP203 equipped trucks. Chain stretch can occur over time, but the reliability of the chain is not a major concern in everyday applications, especially if the transfer case has been converted to part time. Regardless, it is nowhere near as popular as the New Process NP205. NP205/NP203 doubler kits (mounting the two transfer cases together) are often used by off-roaders seeking to reduce their gearing significantly.

New Process NP203 Specs

Manufacturer New Process Gear
Applications • 1974 - 1979 Ford pickups
• 1974 - 1979 Dodge pickups
• 1973 - 1979 GMC/Chevrolet pickups
Case Cast iron, sectional (four pieces mated together), married & divorced variations
Drive Type Full time, chain driven, manual shift
Gear Ratios High Range 1.00 : 1 (direct drive)
Low Range 2.00 : 1
Fluid Type/Spec 10W-30 motor oil
Weight 160 - 170 lbs dry
Identification Transfer case ID tag located on front of case above 4WD output shaft

Because the NP203 is a full time transfer case, it has a unique shift pattern. The driver is able to select (from front to rear) Lo-Loc, Low, Neutral, High, and Hi-Loc. In the Hi/Low "Loc" positions, the differential in the transfer case is locked, distributing power equally between the front and rear axle. In the Low/High positions, the differential allows the front and rear axles to receive drive power independently of one another depending on the driving conditions (i.e. it is possible that only the front axle or only the rear axle is transmitting power at a given time).