One problem related to mechanical jack has been reported for the 2002 GMC Envoy. The most recently reported issues are listed below.
The jack on the 2002 GMC Envoy 4x4 is not adequate for the vehicle. It has to be placed in a very limited number of locations under the vehicle, and will not work at all unless the pavement is absolutely flat (no cracks in the cement!). My vehicle was sold new with skid plates for off-roading, but the jack is totally unusable on a dirt surface and it sometimes even on pavement won't jack the vehicle high enough to get the tire off the ground.