WenmarOpen by Wenmar Pro

Service bulletin 040421002

A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.

The communication, as NHTSA indexes it (as of 2026-10-19)
TypeService bulletin
NHTSA id10012181
Published by NHTSA2005-02-17
Manufacturer's number040421002
Manufacturer's date2006-01-01
Replaces040421002A
NHTSA componentPOWER TRAIN:AUTOMATIC TRANSMISSION

NHTSA's summary

NOISE AND BUMP CLUNK FELT WHEN TRANSFER CASE SHIFTED INTO FOUR LOW. *EH

The document

No address for NHTSA's copy can be built for this communication. Ask the dealer for it by the manufacturer's number.

Components

Transmission and driveline, Automatic transmission

Vehicles listed
CHEVROLET COLORADO2004, 2005, 2006
GMC CANYON2004, 2005, 2006

Listing a model year does not mean every vehicle of it is concerned: the document says which.

Other bulletins for the same vehicles and component
06-00-89-031D2021-09-07. Service bulletin. OEM and Remanufactured Engine and Automatic Transmission/Transaxle Identification
06-00-89-031D2021-04-20. Service bulletin. OEM and Remanufactured Engine and Automatic Transmission/Transaxle Identification
1308116001F2020-12-07. Service bulletin. The intent of this technical bulletin is to identify aftermarket ALDL or DLC interface devices as potential sources for causing multiple customer concerns that do not have other diagnostic methods to identify them.
PIP3366C2018-08-20. Service bulletin. This Preliminary information communicates to the dealer technician thatLight Duty Trucks equipped with automatic transmissions and 4 wheel drive may exhibit a condition of grinding/ratcheting type noise when shifting the automatic transmission into park while the transfer case is in 4 wheel drive low (4LO) range. Dealers technician's are advised this condition should be deemed a normal characteristic of 4WD low operation.
09-07-30-018D2018-06-04. Service bulletin. This informational bulletin provides a revision for 09-07-30-018C to add the 2014 model year and update the Labor Operation.
01-00-89-010J2018-05-21. Service bulletin. This informational bulletin provides a revision for 01-00-89-010I to add the 2013 model year.
01-07-30-042H2018-05-21. Service bulletin. This information was created to inform the technician that the 2-3 upshift and the 3-2 downshift clunk is caused by the releasing of the 2-4 band and application of the 3-4 clutch assembly during an upshift. Also during a 3-2 downshift, the releasing of the 3-4 clutch during the application of the 2-4 band, can cause torque reversal down the output shaft creating a clunk. This is a normal condition.
1203100022017-12-22. Service bulletin. This informational bulletin provides a description of the proper wheel installation and proper wheel torque techniques used to install wheels onto vehicles
09-07-30-018C2017-10-12. Service bulletin. This warranty administration bulletin provides information on the change in automatic transmission add conditions documentation and claim submissions
02-07-30-052J2017-08-15. Service bulletin. This informational bulletin provides technicians with information regarding automatic transmission oil cooler flow test essential tool J-45096 TransFlow®.