Forum Discussion

Sturgeon-Phish's avatar
Jun 03, 2015

GM Pump Rub in Transfer Case

GM transfer cases 261 and 263 are prone to a condition known as Pump Rub. It is where the pump used to circulate the fluid in the transfer case wiggles back and forth wearing a hole in the transfer case, allowing fluid to leak out and if not caught the loss of fluid will destroy the transfer case.
Know of this condition I installed a modification to prevent the pump rub, but I was too late and had a hole in my transfer case not knowing it. I still had plenty of fluid so the damage was limited to the case housing.
I am currently in the process of replacing the damaged transfer case housing with the pump rub mod to prevent damage in the future.

My point is to frequently check the fluid level in your transfer case, and at the first sign of leakage if you see any, perform the pump bub fix.
Jim
  • We took our 2006 Duramax in and had to condition fixed before it became a problem. We plan on keeping the truck so it needed to remedied.
  • Where did you find a new housing? My brother has the same problem and all he has been able to locate are entire transfer cases.
  • I have heard many stories about pump rub, but have had no issues yet.
    I have one truck with 360,000 miles and one with 145,000. I thought about doing the upgrade, but I just keep an eye on it.