Rattle Noise and/or Trans Fluid Leak from Trans Cooler Line Contact with Catalytic Converter - kw 4L60E oil transmission

When servicing the vehicle with the VIN you entered, the following diagnosis might be helpful if the vehicle exhibits the described symptoms.

This message is In regards to 2002 - 2003 - 2004 Chevrolet TrailBlazer, TrailBlazer EXT/GMC Envoy, Envoy XL /Oldsmobile Bravada and Buick Rainier models equipped with the 4.2 liter LL8 engine. Some customers may comment about a rattle noise underneath the vehicle, or an automatic transmission fluid leak. The rattle noise may be due to a hard contact between one of the transmission oil cooler lines and the exhaust catalytic converter. This hard contact, may eventually lead to a hole in the coolant pipe and leakage of automatic transmission fluid. Replacement coolant lines from GMSPO, part numbers 15196379 inlet, and part number 15196383 outlet, can continue to be used as service replacement parts, but they need to be carefully bent to provide 10 mm of clearance near the catalytic converter. As of 10/1/2003 both Moraine and OKC assembly are building with new transmission oil coolant pipes, which provide appropriate clearance. A Service Bulletin will be released as soon as the new pipes are available from GMSPO.

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Please follow this diagnosis process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed. If these steps do not resolve the condition, please contact GM TAC for further diagnostic assistance. This diagnostic approach was developed for the vehicle with the VIN you entered and should not be automatically be used for other vehicles with similar symptoms.

(2002-2004 Chevrolet Trailblazer 2WD/4WD) and (2002-2004 Chevrolet Trailblazer Ext. 2WD/4WD) and (2002-2004 GMC Envoy 2WD/4WD) and (2002-2004 GMC Envoy XL 2WD/4WD) and (2002-2003 Oldsmobile Bravada AWD) and (2004 Buick Raineir 2WD/4WD)

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