The plastic housing on my winch assembly shattered, so I was searching here for advice and part numbers.
The GM number 25911640 appears to still be valid, but be aware that there is an aftermarket replacement also.
Dorman used to be a fine company, now they primarily sell Made-In-China junk. Ordinarily I'd avoid a Dorman product (or at least buy with scepticism) but since the "Genuine GM" item is also a high-failure piece of crap which is probably also made in China, I figured "why not".
Consider Dorman # 924-509. Some variation of this part number will probably get you a Dorman-sourced part at NAPA, CarQuest, O'Reileys, etc.
I just ordered mine from Amazon. Less than $100, shipped to my door.
Seems to fit all Trailblazer/Envoy/Rainier/Saab/Isuzu 2002--2009. Verify for yourself:
"Limited lifetime warranty".