Service Update for Inventory Vehicles Only - Transfer Case to Adapter Gasket Omitted-Expires June 30, 2007

THIS SERVICE UPDATE INVOLVES VEHICLES IN DEALER INVENTORY ONLY AND WILL EXPIRE JUNE 30, 2007.

This bulletin provides a service procedure to inspect for and, if necessary, install a transfer case adapter gasket on certain 2007 GMC Sierra Denali vehicles, equipped with AWD and 6L80 (RPO MYC) automatic transmissions. These trucks may have been built without the transfer case to adapter gasket, which is required in order to prevent galvanic corrosion from occurring between the magnesium transfer case and the aluminum adapter.

This service procedure should be completed on involved vehicles currently in dealership inventory as soon as possible but no later than June 30, 2007, at which time this bulletin will expire.

A list of involved vehicles currently in dealer inventory is attached to the Administrative Message; and will be available on the "Service Update Bulletin Information" link under the "Service" tab in DealerWorld (US) on Tuesday 3/20/07; or attached to the Dealer Communication (Canada), used to release this bulletin.

Important: Dealers are to confirm vehicle eligibility prior to beginning repairs by using GM Vehicles Inquiry System (GMVIS).

Parts required to complete this service update are to be obtained from General Motors Service and Parts Operations (GMSPO). Please refer to your "involved vehicles listing" before ordering parts. Normal orders should be placed on a DRO = Daily Replenishment Order. In an emergency situation, parts should be ordered on a CSO = Customer Special Order.

Important: Due to the small number of vehicles involved, dealers are encouraged not to order parts for use as shelf stock. Parts should only be ordered when involved vehicles are verified from the VIN list, and inspection determines that it is necessary to install the Transfer Case Adapter Gasket.

1. Raise and suitably support the vehicle. Refer to Lifting and Jacking the Vehicle in SI.





2. Inspect for transfer case to transfer case adapter gasket. If the gasket is present (1), no further inspection or repairs are needed. If the gasket is not present (2), proceed to step 3.

Important: When installing a new transfer case adapter gasket, the gasket must be installed with the tab oriented up, and the yellow printing towards the front of the vehicle. Install the gasket without the use of any type of sealant or lubricant.

3. Remove the transfer case and install the gasket. Refer to Transfer Case Assembly Replacement in SI.

For vehicles repaired under this service update, use: