NV241HD Transfer Case

DESCRIPTION
The NV241HD is a part-time transfer case with a low-range gear system. The transfer case provides three operating ranges plus a Neutral position. The low range position provides a gear reduction ratio of 2.72:1 for increased low speed torque capability. Operating ranges are: 2-high, 4-high and 4-low.

Fig. 1 (Part 1 Of 2):

Fig. 1 (Part 2 Of 2):

The synchronizer mechanism consists of a brass stop ring, synchro hub, and the sliding clutch (Fig. 1). The synchronizer components allow the transfer case to be shifted between the 2H and 4H operating ranges while the vehicle is in motion.
The gear cases, retainer and extension are all of aluminum. Drive sprockets and an interconnecting drive chain are used to transmit engine torque to the front/rear propeller shafts. The mainshaft, input gear and front output shaft are supported by ball and needle bearings.

PTO CAPABILITY
The NV241HD transfer case has power take-off capability. A PTO gear permanently attached to the planetary carrier, and a removable PTO cover are provided for this purpose.

IDENTIFICATION

Fig. 2:

An identification tag (Fig. 2) is attached to the rear case of every transfer case. The tag provides the transfer case model number, assembly number, serial number, and low range ratio.
The transfer case serial number also represents the date of build.

OPERATION
OPERATING RANGES
Transfer case operating ranges are:
^ 4x2 (2-wheel drive)
^ 4x4 (4-wheel drive)
^ 4 Lo (4-wheel drive low range
The 4x2 range is for use on any road surface at any time.
The 4x4 and 4 Lo ranges are for off road use only. They are not for use on hard surface roads. The only exception being when the road surface is covered by ice and snow.
The low range reduction gear system is operative in 4 Lo range only. This range is for extra pulling power in off road situations. Low range reduction ratio is 2.72:1.
A front axle disconnect system is used to achieve two-wheel drive mode. The axle disconnect vacuum motor is actuated by a vacuum switch on the transfer case. The switch is operated by the transfer case range rod.

SHIFT MECHANISM
The transfer case is operated by an adjustable floor mounted shift linkage. The transfer case shift lever is directly attached to the shift sector. The sector operates the range and mode forks within the transfer case.
A straight line shift pattern is used with a neutral detent. Lever range positions are imprinted in the shift knob.

SHIFTING
The synchronizer components allow the transfer case to be shifted between the 2H and 4H operating ranges while the vehicle is in motion. The vehicle must have the transmission placed in neutral, or the clutch depressed in the case of a manual transmission, and be moving less than 2-3 MPH when shifting into the 4L operating range.