GM-GMC: 2000 Chev 2500, clutch pack, greenish color

Question
The complete four wheel drive unit was serviced by an independent service shop. They replaced all the fluids to factory specs.
The "Service 4 wheel drive" light still comes on, only occasionally.
What could be causing that. Your help would be greatly appreciated.
artl@best.com

Answer
I'm guessing that this truck is equiped with an automatic transfer case. Does it have a "Auto 4wheel" button on the select switch? If so it could be a problem with the transfer case or the actuator motor either in the transf. case or on the front axle. GM has had a lot of problems with the front actuators and I believe there is even a change-up in design in these actuators. It may or may not be for your aplication. Also make sure the the shop used the proper tansfercase oil, it is a full synthetic only available from GM, it is usually a greenish color, its very important this is used since there is a clutch pack inside these transfer cases. Now, I hate to do this, but from experience if the problem persists i would take the truck back to the dealer. I work at a private shop myself and unless equipt with a GM scan tool diagnosing this may take much longer then it should. Generic scanners can not comunicate with the proper module like the GM scan tool and therefore a problem can be found much faster by someone that has access to all the vehicle data! Hope this helps!