Transfer Case - High Shift Effort When Cold
NO.: 21-25-94GROUP: Transmission
DATE: Dec. 23, 1994
SUBJECT:
High Effort when Shifting from 2WD High to 4WD High, in Cold Ambient Temperatures
MODELS:
1994 - 1995 (BR) Ram Truck
NOTE:
THIS BULLETIN APPLIES TO BR VEHICLES EQUIPPED WITH NP231 HD, NP241, OR NP241 HD TRANSFER CASE.
SYMPTOM/CONDITION:
High shift effort, condition occurs during cold weather operation while shifting the transfer case into 4WD High from the 2WD High mode.
DIAGNOSIS:
With vehicle cold (below 30 degrees F), shift transfer case from 2WD High to 4WD High with the vehicle stationary. It may be necessary to move vehicle slightly forward or rearward to engage front axle.
If transfer case does not shift with the vehicle stationary, check external shift linkage for proper adjustment. Reference appropriate Ram Truck Service Manual for transfer case shift linkage adjustment procedure.
With vehicle still cold, attempt to shift from 2WD High to 4WD 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 4WD High mode for approximately 10 miles. Shift transfer case from 2WD High to 4WD High several times. Allow time between shifts to ensure synchronizer is out of the 4WD High mode before shifting.
NOTE:
AVOID SHARP TURNS ON HARD DRY SURFACES WHILE TESTING VEHICLE.
If vehicle exhibits high shifting effort in cold weather operation (below 30 degrees F), but has reasonable effort and consistency after axle lube is warm, perform the front axle lubricant fill procedure listed.
If Vehicle requires high shifting effort and shifts inconsistently after the front axle lubricant is warm, the following transfer case parts require replacement in addition to the front axle lubricant change.
PARTS REQUIRED:
Front Axle Lubricant
AR 4467707 Mopar High Performance Synthetic Axle Lube (amount specified
by transfer case.)
REPAIR PROCEDURES:
This bulletin involves replacing the lubricant in the front axle, and in some cases, replacing the above listed parts in the transfer case.
FRONT AXLE LUBRICANT REPLACEMENT:
1. Using a suction pump, remove as much 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 as specified below.
BR Truck - 4F Axle
Fill to within 1/4" of the bottom of the fill plug hole (approximately 77 ounces).
BR Truck - 6OF Axle
Fill to within 1/2" of the bottom of the fill plug hole (approximately 122 ounces).
NOTE:
OVERFILL CAN RESULT IN LUBRICANT "FOAMING" AND/OR UNIT OVERHEATING.
TRANSFER CASE COMPONENT REPLACEMENT:
1. After completing the above front axle lubricant change, test the shifting effort.
2. If high shifting effort or inconsistent shifting is occurring, replace the synchronizer assembly referencing Group 21 in the appropriate Service Manual.
POLICY:
Reimbursable within the provisions of the warranty.
TIME ALLOWANCE:
Labor Operation No: 21-03-01-93 (Fluid, Front Axle-Replace, 1994-1995) 0.3 Hrs.
21-03-01-94 (Synchronizer, Replace, 1994-1995) 2.1 Hrs.
Optional Equipment
21-03-01-60 (Skid Plate Equipped, 1994-1995) 0.4 Hrs.
FAILURE CODE: P8 - New Part