Description
Fits: 2001 thru 2007 Chevy Silverado/GMC Sierra 2500HD/3500HD LB7/LLY/LBZ Duramax Diesel
Upgrade your GM transfer case to avoid the increasingly common issue of pump rub. This critical enhancement ensures the longevity and reliability of your vehicle’s transfer case, protecting it from potential damage and costly repairs. This kit is compatible with GM transfer cases 261XHD (Manual Shift) and 263XHD (Electronic Shift).
What is Pump Rub?
GM transfer cases feature a pump cover inside the case, driven by the main shaft. This pump circulates oil to the planetary gears and the drive sprocket sleeve. Since the pump is shaft-driven, its housing must “float” within the rear housing, guided by five tabs that fit into designated spots. Over time, the pump can wear against the rear housing. GM installed a spring steel clip in the housing to prevent this wear, but the clip can break and become ineffective.
As the pump housing is made of Magnesium, which is a soft metal, it can eventually wear a hole in the rear housing, causing a small leak. This leak typically occurs high enough in the case that it won’t be noticeable when the vehicle is stationary, leaving no drops on the ground. Often, the issue is only discovered after the transfer case sustains damage from running out of fluid.
Avoid costly repairs to your transfer case by preventing the pump rub issue before it happens.
How to Prevent Pump Rub
Pump Rub is preventable if you catch it early enough. There are a few paths that you can navigate when addressing this common issue.
The first is to upgrade the GM internal pump cover using DmaxStore’s Transfer Case Upgrade Kit. Within this kit, we have machined our own Billet T6-6061 Aluminum pump cover with a far superior design than any OEM replacement. DmaxStore took note of the thin OEM tangs on the stock pump cover and designed one that has much larger tangs. For reference, the width of the OEM tangs is approximately 2.1mm, and the DmaxStore replacement pump cover has tangs that are 15.24mm. This design ensures that there are no cutting patterns in the transfer case when it is operational since there is more surface area being covered within the pump cover housing.
The second way to fix this issue is to replace the back half of the transfer case. There will come a point when the damage to the transfer is too severe, and the only option is to replace it. Fortunately, we offer our
