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Merchant Automotive Transfer Case Pump Upgrade Kit & Fluid

Merchant Automotive

$99.99
SKU:
10057
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To repair or prevent pump rub failure on your transfer case, use this Merchant Automotive Transfer Case Pump Upgrade Kit with Performance Transfer Case Fluid. It is designed for 1998-early 2007 GM transfer cases, including the NP261XHD and NP263XHD used in 2001-2007 Chevy Silverado and GMC Sierra 2500HD and 3500HD trucks with the 6.6L Duramax diesel (LB7, LLY and LBZ), and the transfer cases used in 1998-early 2007 Cadillac, Chevrolet and GMC gas trucks and SUVs with 4WD or AWD, including the NP136, NP149, NP236, NP246, NP261, NP261HD, NP263 and NP263HD.

This kit gives you what you need to help prevent future failures, and it can be installed as part of a repair to replace the affected parts. It combines our Transfer Case Pump Upgrade Kit with 2 quarts of our performance transfer case fluid, enough for a single fill of a typical GM HD transfer case with no waste. The pump housing is engineered and machined in house by Merchant Automotive in Holland, Michigan, as part of our focus on the Duramax and Allison platforms.

Note: This kit is designed to work with OE magnesium case halves and may not be compatible with some aftermarket aluminum rear transfer case halves due to inconsistent manufacturing tolerances. Verify fitment before installation.

Features

  • All in one kit for upgrading your transfer case pump
  • Merchant Automotive T-6061 aluminum CNC machined pump housing replaces the factory housing
  • Includes the gasket, RTV silicone and threadlocker for installation
  • 2 quarts of Merchant Automotive Performance Transfer Case Fluid, one fill for most GM HD transfer cases
  • Replaces OE parts with performance upgrades
  • Limited lifetime warranty against pump rub

What's Included

Performance Transfer Case Fluid

At Merchant Automotive, we are all about increasing the performance of your truck. Here is how our performance transfer case fluid can help:

  • Blended specifically for use in GM transfer cases
  • Promotes transfer case and shifting performance
  • Dramatically reduces wear on internal components and seals
  • Increases component efficiency
  • Reduces irritating driveshaft clunk and clutch chatter
  • Performs in manual or electric shift applications, gas or diesel
  • Cost effective upgrade for Auto Trak II

What is Pump Rub?

Pump rub refers to a gear pump failure in GM transfer cases from 1998 through 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 must "float" in the rear housing of the transfer case, held in place by tabs that fit into the rear housing. Over time, these tabs can wear on the rear housing, and the pump housing can wear through it and cause a small leak. Due to the location of the leak, many trucks do not drip while parked, only while driving, so it can go unnoticed. These transfer cases do not have a low fluid indicator, so by the time the problem is noticed, it is usually too late.

From the factory, GM installed a spring steel clip in the housing to prevent this wear, but it can break and stop doing its job. Installing this upgrade kit can help you prevent pump rub before it happens and avoid costly repair bills, and it comes with a limited lifetime warranty against pump rub.

Before You Order

Installation Tips

  • Discard the OEM anti rattle clip during installation. The pump housing is designed and precision machined to work with the clip removed.
  • After reassembly, make sure the rear output bearing snap ring is fully seated in the rear housing and in the locating groove in the bearing.
  • Refill the transfer case with the included performance transfer case fluid.

Installation Resources

Related Parts

Frequently Asked Questions

What do I do with the OEM anti rattle clip when installing this upgrade?
Discard the factory clip during installation. The MA Transfer Case Pump Upgrade Kit has been designed and precision machined to work with the clip removed.

What other parts will I need to install this upgrade kit?
The kit is designed to be all inclusive for a basic installation when it is installed as a preventative measure. If it is being installed as part of a repair or after pump rub has occurred, there is no real way to know the extent of the damage until the case is completely disassembled. In many cases, as long as the case has not run out of fluid, it can be repaired with a new rear housing and seal. Either way, refill the case with the included Merchant Automotive Performance Transfer Case Fluid.

I hear a grinding noise at low speed after installing the kit. What could that be?
A low speed grinding noise is most commonly caused by the rear output bearing snap ring not being fully seated, which lets the bearing move out of alignment. Verify that the snap ring is fully engaged and seated in the rear housing and in the locating groove in the bearing.

What would cause a speed sensor correlation code after installing this upgrade?
A speed sensor correlation code often comes with a low speed grinding noise and is frequently caused by the rear output bearing snap ring not being fully seated. Verify that the snap ring is fully engaged and seated in the rear housing and in the locating groove in the bearing.

How much fluid does my transfer case need?
A typical GM HD transfer case takes 2 quarts, which is what this kit includes. Always confirm your transfer case's capacity in the owner's manual.

For warranty information, see our Warranty Policy.

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