The Envoy one day started a clicking noise from the center of the dash when I would start it up. It would last only a few seconds. I started pushing the buttons for the vent operations and it would do it then. After doing some online research and looking under the dash while operating the door I determined it was the mode door actuator (the clicking is the motor in the actuator going bad). I also learned that only the 2002 Envoy had to have a puller to remove the old actuator. After purchasing the replacement part and finding out the price for a puller ($60 ebay -$160 dealer)I thought about a beam clap that can be bought for .89 cents at Lowes or Home Depot in their electrical dept. Taking a grinder I was able to make it fit over the new part and I had to flex the clap so the jack bolt would line up with opening for the shaft, all of 15 minutes. Puller worked like a charm and after about and 1 1/2 hour it was in and everything was operating.