I have an 02 Envoy that is the same set up as the TB. 49,000 miles. I'm having trouble with the clutch fan. It must be stuck because it sounds like a jet engine when you get it some gas. Have heard that the fan isn't faulty and all it needs is software update or it's shot and the clutch fan needs to be replaced. To me this is one extreme to the other so I need to find out exactly what the problem is and what the fix is. Anyone else have this problem? I looked and there is no oil leaking from the clutch. What's the best way to go? Thanks for your help.

If it is locked up all the time it is bad, occasional unexpected lock up that goes away after a few minutes is considered normal, but there is a program up date that can minimize that.

What size wrench does it take to remove the fan?

Read my other reply about fan clutch tool.

When you replace your clutch, make sure you get the new part number (all dealers have them, just dont get a used clutch from a junkyard) and have the dealer reflash your PCM with the most current software calibration which includes an update for the new fan clutch. It doesnt hurt to do this first and make sure it cant be fixed by only a software upgrade, it has worked for some.