Rainier AWD L6-4.2L (2007)
Transfer Case Actuator: Customer Interest
Drivetrain - Transfer Case Grinds In 4WD/AWD
TECHNICAL
Bulletin No.: 08-04-21-001B
Date: August 25, 2008
Subject:
NVG 126/226 Transfer Case Grating/Grinding Noise When 4WD is Engaged, Service 4WD Lamp On, DTC C0327 Set (Replace Clutch Pressure Plate
Bearing Assembly and Clutch Lever)
Models:
2004-2007 Buick Rainier
2002-2008 Chevrolet TrailBlazer Models
2002-2008 GMC Envoy Models
2002-2004 Oldsmobile Bravada
2005-2008 Saab 9-7X
with Four-Wheel Drive or All-Wheel Drive and Active All-Wheel Drive (RPO NP4) or Active Two-Speed (NP8) Transfer Case
Built Prior to September 18, 2007 (NVG 126) or September 21, 2007 (NVG 226)
Supercede:
This bulletin is being revised to update the correction information to include a procedure to reindex the transfer case encoder motor (actuator). This
procedure is being provided to help reduce unnecessary warranty expenses. Please discard Corporate Bulletin Number 08-04-21-001A (Section 04 -
Transmission/Transaxle).
Condition
Some customers may comment on a grinding type noise in the transfer case when 4WD is engaged in either AUTO or 4WD mode. This noise may also
be accompanied by the SERVICE 4WD lamp being illuminated and DTC C0327 set.
This condition is more prevalent on vehicles where 4WD is continuously used.
Cause
This noise may be caused by a faulty clutch pressure plate bearing.
Correction
A more robust clutch pressure plate bearing, inner plate and clutch lever has been released for service. Replace the clutch pressure plate bearing,
inner plate and clutch lever. Refer to the Transfer Case Disassemble and Transfer Case Assemble procedures in SI. Former and new parts should
not be intermixed during transfer case overhaul and they are to be used in sets only.
DO NOT replace the transfer case assembly unless extensive internal damage has occurred.
Important:
When the clutch pressure plate bearing fails, it causes the clutch lever to over-travel, allowing the transfer case encoder motor (actuator) to
rotate to an invalid position. Engineering has developed a tool and procedure to reindex the transfer case encoder motor (actuator) so it can be
reused. Use the specific procedure listed below.
NVG 126 Transfer Case Encoder Motor (Actuator) Indexing Procedure
Tools Required:
^
(1) EL-49741 9 Volt Encoder Motor (Actuator) Jumper Harness (Tool can be obtained from SPX/Kent Moore.
^
(2) J-356165 Terminal Test Adapter (Test Probe)
