Sierra Classic 2500 4WD V8-6.0L (2007)
NVG 263 Variations
The HD and the SHD model share many of the same components, but the increased torque capacity of the SHD requires a double row input bearing,
larger diameter rear output shaft, rear output shaft bearing higher capacity, larger rear seal and case halves machined differently.
2WD Mode Power Flow
The transfer case is shifted by an encoder motor (9) on the shift detent lever shaft. The shift detent lever shaft rotates the cam shaped shift detent lever
(10) and moves the high/low range shift fork (11) or the 2/4 wheel drive mode shift fork (8). Depending on the selected mode or range, the shift forks
move either the high/low range sleeve (4) for the high/low range planetary assembly (3) or the synchronizer sleeve (6) for the 2/4 wheel drive mode. In
2WD mode, the engine power from the transmission (1) is delivered to the input shaft (2). The engagement teeth on the inside of the input shaft (2) are
engaged to the outer teeth on the high/low range sleeve (4). The high/low range sleeve (4) is slip splined to rear output shaft (5). The engine power
flows from the high/low range sleeve (4) to the rear output shaft (5) and delivered to rear propeller shaft (7).
