Grand Cherokee 4WD V8-4.7L VIN N (2000)
Technical Service Bulletin # 03-05-00
Date: 000721
Axle, Front - Whine and/or Moan Noise
NUMBER: 03-05-00
GROUP: Axle
DATE: July 21, 2000
SUBJECT:
Quality Improvements To Address Front Axle Whine And 2,400 RPM Moan
OVERVIEW:
This bulletin involves the replacement of the front propshaft, axle yoke, and transfer case yoke. This bulletin also involves selectively erasing and
reprogramming the Transmission Control Module or TCM (with calibration 99Ver9.0 or 00Ver9.0), and if necessary, reprogramming the Powertrain
Control Module or PCM (with calibration 99Cal19A or 00Cal16A).
MODELS:
1999-2000 (WJ) Grand Cherokee
NOTE:
THIS BULLETIN APPLIES TO VEHICLES EQUIPPED WITH A 4.7L ENGINE AND EITHER A NV247 OR A NV242HD TRANSFER CASE.
SYMPTOM/CONDITION:
The customer may experience powertrain related sound(s) which may be described as front axle whine or as 2,200 to 2,400 engine rpm moan. One or
both sounds may be noticed at the same time or separately during different modes of driving.
The front axle whine-like sound may occur during any vehicle speed and during acceleration, coast, or float driving modes.
The moan-like sound will normally occur when the transmission is in top gear (overdrive) and the engine is running between speeds of 2,200 to 2,400
rpm. The moan-like sound will normally fade in and out (beat) while the throttle is held in a steady state or when the throttle is being depressed to
accelerate the vehicle. The beat may increase in frequency as the engine speed increases. The moan-like sound will not occur if the transmission is
shifted to a lower gear (overdrive button depressed) or if the throttle is released.
A revised front propeller shaft addresses the whine-like sound from the front axle area.
The revision to the TCM software adds a final gear ratio to the transmission. This new final gear ratio will cause a substantial reduction in the moan-like
sound. Any remaining sound will occur at higher vehicle speeds.
NOTE:
TO MAINTAIN EMISSIONS COMPLIANCE, VEHICLES EQUIPPED WITH A FEDERAL EMISSION SYSTEM (SALES CODE NAA) MUST
HAVE THE PCM REPROGRAMMED IF THE PCM CALIBRATION LEVEL IS EARLIER THAN 99CAL19A OR 00CAL16A.
REPROGRAMMING IS NOT REQUIRED IF THE PCM SOFTWARE IS ALREADY AT ONE OF THESE LEVELS (OR LATER) OR IF THE
VEHICLE HAS A CALIFORNIA EMISSION SYSTEM.
NOTE:
WHENEVER A POWERTRAIN CONTROL MODULE OR A TRANSMISSION CONTROL MODULE IS REPLACED DUE TO FAILURE,
THE SOFTWARE OF THE REPLACEMENT CONTROLLER MUST BE VERIFIED FOR THE LATEST REVISION LEVEL. USE THE FLASH
PROCEDURE TO UPDATE REPLACED CONTROLLERS AS NECESSARY.
DIAGNOSIS:
1.
If one or both of the above symptoms has been experienced on the vehicle in question, then perform the Repair Procedure.
2.
Refer to Technical Service Bulletin (TSB) 03-05-9 if additional axle diagnosis is required.
