Manufacturer communication — 2006 GMC YUKON DENALI XL

• Applies to GM passenger cars and trucks, model years 2000 to 2023.

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  GM Passenger Cars and Trucks 2000 2023

• A noise comes from underneath a vehicle equipped with an automatic transmission.

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  Some customers may comment on a noise coming from underneath the vehicle equipped with an automatic transmission.

• The technician may find that the noise comes from the bell housing area.

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  Technicians may find that the noise is coming from the bell housing area.

Possible causes

• Running the engine with those bolts removed may damage the pilot on the front of the torque converter, the pilot hole in the end of the crankshaft, or both.

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  Damage may occur to the pilot on the front of the torque converter or the pilot hole in the end of the crankshaft or both if the engine is running with the flex plate to torque converter bolts removed.

Steps to confirm (in the document’s order)

• Use chassis ears to isolate the component or assembly that is the loudest source of the noise.

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  It is recommended to use chassis ears to isolate the component or assembly that is the loudest source of the noise.

Caution

• Do not separate the torque converter from the flex plate.

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  Do Not separate the torque converter from the flex plate.

• Do not remove the flex plate to torque converter bolts, push the converter back and start the engine to tell whether the noise is from the engine or the transmission.

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  It is not recommended to remove the flex plate to torque converter bolts, push the torque converter back towards the transmission and start the engine to determine if the noise is coming from the engine or the transmission.