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Transfer Case - High Effort Shifting From 2-H to 4-H

87chrysler6

Models


1985-1987 "W" & "AW" Trucks With NP208 Transfer Case & "N" Body 4 x 4 With NP207 Transfer Case


Subject


High Shift Effort When Shifting From 2-High to 4-High


Index


TRANSMISSION


Date


August 17, 1987

No..


21-15-87 (C10-21)

P-2869
SYMPTOM/CONDITION

High shift effort or total block out while shifting into 4-High (four-wheel drive transfer case). Condition occurs during cold weather operation while shifting the transfer case into 4-High from the 2-High mode.

DIAGNOSIS

With vehicle cold (below +30~F), shift transfer case from 2-High into 4-High with the vehicle stationary. It may be necessary to move vehicle slightly forward or rearward to engage front axle.

If the transfer case does not shift with the vehicle stationary, check external shift linkage for proper adjustment (see appropriate service manual for transfer case shift linkage adjustment procedure).

With vehicle still cold, attempt to shift from 2-High to 4-High at approximately 25 mph. While shifting, apply a constant force to the transfer case shift lever, not a quick pull. This will allow the synchronizer time to get the front propshaft up to speed. With cold front axle lubricant, the vehicle may require high effort for an extended time, or will not shift.

Warm front axle lubricant by operating vehicle in 4-High mode for approximately 10 miles. Shift transfer case from 2-High to 4-High several times. Allow time between shifts to insure synchronizer is out of the 4-High mode before shifting.

If vehicle exhibits high shifting effort in cold weather operation (below +30~F), but has reasonable effort and consistency after vehicle is warm, perform the front axle lubricant fill procedure as outlined later in this bulletin.

If vehicle requires high shifting effort and shifts inconsistently after the front axle lubricant is warm, the following transfer case parts might require replacement, in addition to the front axle lubricant change.

PARTS REQUIRED

Transfer Case - NP208 ("W" and "AW" Truck)

1 Synchronizer Assembly PN 4329516
1 Drive Sprocket Assembly PN 4329527

Transfer Case - NP207 (N5 Dakota 4 x 4)

1 Synchronizer Assembly PN 4446457
1 Drive Sprocket Assembly PN 4446453

Front Axle

Mopar High Performance Synthetic PN 4467707
Axle Lube (1 quart can)

REPAIR PROCEDURES

This procedure involves replacing the synchronizer assembly and axle lube.

Transfer Case

See appropriate service manual for replacement procedures.

Front Axle

1. Using a suction pump, remove as much of the axle lubricant as possible.

NOTE: IT IS NOT NECESSARY TO REMOVE THE DIFFERENTIAL COVER.

2. Refill the axle with Mopar High Performance Synthetic Axle Lube, PN 4467707, as specified below.

"W" and "AW" Truck:

Fill to within 1/4" of the bottom of the fill plug hole (approximately 84 ounces).

N5 Dakota 4 x 4:

Fill to 1/2" below the bottom of the fill plug hole (approximately 40 ounces).

NOTE: OVERFILL CAN RESULT IN LUBRICANT "FOAMING" AND/OR UNIT OVERHEATING.
POLICY: Reimbursable within the provisions of the warranty


TIME ALLOWANCE: Refer to Labor Operation Time Schedule for operation and time