The Merchant Automotive Transfer Case Pump Upgrade and Repair Kit with Pump and Seal Driver is an all-in-one kit for repairing a 261XHD or 263XHD transfer case that needs a new rear case because of pump rub. It fits 2001-2007 Chevy Silverado and GMC Sierra 2500HD and 3500HD trucks with the LB7, LLY and LBZ 6.6 Liter Duramax diesel, as well as 8.1 Liter gas trucks equipped with the Allison transmission. It includes a new OEM magnesium rear housing, a new pump with our billet pump housing, a rear output seal driver, all of the seals and snap rings, and our magnetic drain plug kit and fluid.

Pump rub is a prevalent problem on 2001 to early 2007 GM transfer cases, and preventing it before it happens is always a good idea. If your case has not failed yet, our basic Transfer Case Pump Upgrade Kit can be installed as preventative maintenance. If your rear housing has already been damaged by pump rub, this kit has everything you need to repair it and prevent it from happening again.

When properly installed, this kit is backed by a Merchant Automotive Limited Lifetime Warranty against pump rub failure.

Features

• All-in-one kit to repair pump rub damage and prevent it from coming back
• Direct replacement, stronger than factory
• New OE-style magnesium rear transfer case housing
• Merchant Automotive billet T-6061 aluminum CNC-machined pump housing
• New 49 spline pump assembly included
• Merchant Automotive rear output seal driver included
• Includes all seals, snap ring, grommet and 9 Inch snap ring pliers
• Magnetic drain plug kit and 2 quarts of performance transfer case fluid
• Limited lifetime warranty against pump rub

What's Included

• (1) OEM magnesium rear transfer case housing
• (1) 49 spline pump assembly with the Merchant Automotive billet T-6061 aluminum CNC-machined pump housing
• (1) Merchant Automotive rear output seal driver
• (1) Rear output seal
• (1) Pickup tube seal
• (1) Speed sensor seal
• (1) Output shaft bearing snap ring
• (1) Snap ring hole grommet
• (1) 9 Inch snap ring pliers
• (1) Merchant Automotive magnetic drain plug kit
• (1) Transfer case to transmission adapter gasket
• (1) Merchant Automotive Performance Transfer Case Fluid, 2 qt
• (1) RTV silicone with applicator nozzle
• (1) Blue threadlocker

What Is Pump Rub?

Pump rub is a common gear pump failure in GM transfer cases from 1998 to early 2007. The gear pump forces oil to the planetary and the drive sprocket sleeve. Because the pump is driven by the mainshaft, the pump housing floats in the rear housing and is held in place by tabs that sit in pockets in the rear housing.

Over time those tabs wear into the rear housing and the aluminum pump housing, causing a small leak. The leak usually happens while driving, not while parked, so it often goes unnoticed. These transfer cases have no low fluid warning, so by the time the problem is found, the damage is usually done.

GM installed a spring steel clip to prevent this wear, but the clip often breaks and stops working.

Installing this kit repairs the damage and prevents pump rub from happening again.

Pump Rub Warranty

This kit comes with a Merchant Automotive Limited Lifetime Warranty against pump rub. If you have this kit installed and the pump wears a hole in the new rear housing, we will replace the transfer case. This warranty applies only to installations with a new rear housing, which this kit includes.

Before You Order

Note: A transfer case that has been run without fluid may have additional internal damage that cannot be seen from the outside. Additional parts may be needed.

Installation Tips

• Inspect the internal parts for heat damage or wear while the case is apart, especially if it ran low on fluid.
• Use the included blue threadlocker and RTV silicone as directed during reassembly.
• Use the included seal driver to install the rear output seal straight and to the correct depth.
• Fill with the included 2 quarts of fluid before driving, then check for leaks.

Related Parts

• Transfer Case Pump Upgrade Kit
• Transfer Case Pump Upgrade and Repair Kit, XHD
• Transfer Case Pump Upgrade and Repair Kit with Seal Driver, XHD
• Transfer Case Pump Upgrade and Repair Kit with Pump, XHD
• New 261XHD Transfer Case
• New 263XHD Transfer Case

Frequently Asked Questions

My transfer case has not failed yet. Do I need this kit?

No. If your rear housing is not damaged, our basic Transfer Case Pump Upgrade Kit can be installed as preventative maintenance. This kit is for cases that need a new rear housing.

Does it fit both the 261XHD and the 263XHD?

Yes. It fits both the manual shift 261XHD and the electronic shift 263XHD.

Does it fit 8.1 Liter gas trucks?

Yes. It fits 2001-2007 8.1 Liter gas trucks equipped with the Allison transmission and the 261XHD or 263XHD transfer case.

What is the difference between this kit and the other repair kits?

This is the most complete version. It includes both the new pump assembly and the rear output seal driver.

For warranty information or to submit a claim, see our Warranty Form.

Details:

• Engine Manufacturer: Duramax
• Liter: 6.6 Liter
• Engine Designation: LB7, LLY, LBZ
• Engine Years: 2001-2007
• Transfer Case Model: 261XHD, 263XHD

Applications:

• 2001-2007 Silverado/Sierra 2500HD/3500HD LB7/LLY/LBZ