If you’ve got a 99–07 4WD truck with an NP-series transfer case (the push-button NP246 especially), the oil pump inside has been slowly working against the magnesium case wall since the day it left the factory. Some cases never wear through. Some are scrap at 120K. There’s no way to know which one you have without opening the rear half — and a roughly $100 brace kit ends the question permanently while you’re in there for a fluid change.
BorgWarner-era trucks (mid-2007+) can relax — this one’s not yours.
Full write-up (how to check, kit options, the fluid that matters): GM Transfer Case Pump Rub: The $100 Fix
The community wear database starts here:
- Opened yours? Post the mileage and what the pump contact area looked like — untouched, marked, thin, or holed.
- Which kit did you install, and how was the job — case in the truck or dropped?
- Anyone find the hole the hard way? What did the recovery cost you?
- Photos of wear patterns are gold for the next guy deciding whether to bother. Post them.