Drivetrain - Clunk/Noise Shifting When Into '4LO'
IB08-05-S001Issue Date: JANUARY 2008
Noise And Bump/Clunk Felt When Transfer Case Shifted Into Four Low (4LO)
(This Bulletin Supercedes IB06-05-S003)
Affected Vehicles:
2007-2008 Isuzu i-370 (TI) with 4WD
2006 Isuzu i-350 (TI) with 4WD
Service Information
This bulletin is being revised to add the 2008 model year.
Some customers may comment on a grind noise or a bump/clunk felt when shifting the transfer case into 4L0.
^ The grind/bump/clunk felt when the transfer case electrically shifts into 4L0 is due to the engagement sequence that applies engine torque through the transfer case front differential and front axles.
^ The noise present in all electronically shifted 4WD systems is considered normal operation and does not pose any potential to impart damage by shifting into 4L0.
^ The noise level is louder due to the vehicle size and transfer case design.
^ The noise level can be reduced by following the Owners Manual Instruction of shifting while in neutral and in forward motion of about 4 km/h (3 mph).
^ Alternatively the noise can be eliminated by shifting into 4L0 while in a key on engine off condition.
^ DO NOT REPLACE the transfer case in an attempt to repair this condition.
^ DO NOT attempt to make repairs to the transfer case at this time for this condition.
^ DO NOT attempt to reprogram the transfer case control module (TCCM). The TCCM is NOT REPROGRAMABLE on this vehicle.
^ DO NOT replace the TCCM in an attempt to repair this condition.
^ DO NOT replace the transfer case actuator in an attempt to repair this condition.
^ Dealers are to share this information with concerned customers.
Disclaimer