Where is the jack

Looking at the Owner's Manual it says that the jack is located: on the Regular Models on the rear, driver's side of the vehicle, behind the left trim panel. On the Extended Models is under the storage tray on the driver's side of the vehicle, in the trim panel. For more details, download a copy of the Owner's Manual go to 5-78 Removing the Spare Tire and Tools (p.452) follow this link; http://bit.ly/2006GMCYukon_OwnersManual Hope this helps.

In the rear section just forward of the lift gate on the left side as you face inward is a panel. Unlock and the jack, handle and stand are clipped inside.