Auto Air Conditioning & Heater Repair: Air Con Clutch?, ac performance, big noise

Question
2002 Yukon - when I turn on the AC there is a very loud grinding/rumbling noise until I reach speed.  When I slow to a stop or slow roll and re-accelerate the noise presents.  When the AC is flowing it is nice and cool.  At freeway speed everything works fine but any stop and go = big noise and reduced AC performance.  

If it is the clutch as I suspect, how many hours can I expect to spend on the repair.  I am fairly capable with the wrench.

Thank you,
Jim

Answer
Jim,

I haven't replaced a compressor on that year of Yukon before but if the compressor is still on the top of the engine it should take you about 1.5 hours after system evacuation, and if its on the bottom plan for a few hours depend what you have to remove before the you can get the compressor out. Usually a/c compressors aren't hard to R and R but if you going to just replace the clutch on the compressor you'll need a special a/c clutch puller.