Transfer Case Pump Upgrade Kit

The Ultimate Solution to a problem found in Chevy and GMC light duty trucks and utilities from 1998-2007
The Ultimate Solution to a problem found in Chevy and GMC light duty trucks and utilities from 1998-2007
Price Range:   $75.00 - $113.94
Pump Upgrade Kit: 
Add Magnetic Drain Plugs?: 
Add Transfer Case Fluid?: 
Select Options
To open instructions click here.

Here is the best upgrade you can make to your GM transfer case(model 136, 146, 246, 261, 261HD, 263HD, 263XHD, 261XHD). Prevent the ever increasing problem of pump rub.

What is "pump rub"
The GM transfer cases use a gear pump inside the case that is driven off the mainshaft. The pump forces oil to the planetary as well as the drive sprocket sleeve. Because the pump is driven by the shaft, the housing of the pump must 'float' in the rear housing. There are 5 tabs around the housing that fit into spots in the rear housing to position the pump. Over time, the pump can start to wear on the rear housing. GM installed a spring steel clip in the housing intended to prevent wear but the clip can break and render useless

Being that the pump housing is aluminum and is a harder material then the magnesium rear housing, it can wear a hole in the rear housing and cause a very small leak. This leak is high enough in the case that it typically will not leak when vehicle is not moving and therefor not leaving any drops on the ground. Typically the condition is not found until there is transfer case damage from running the case out of fluid.

Avoid costly repairs to your transfer case by preventing this condition.
Full installation instructions are available right here on this site. Look under the Tech Information link on the home page for step by step directions.
With installation of this kit, you will have a LIMITED LIFETIME WARRANTY against pump rub. If your case ever wears a hole in the new rear housing with the upgrade installed. We will buy you a new transfer case.
Included in the kit:

  • Merchant Automotive billet transfer case pump housing
  • Transfer case adapter gasket at trans
  • RTV Silicone
  • Blue Threadlock
If you already have a hole in your case, its recommended to install a new rear housing for a proper repair. Lifetime warranty will only apply to installations with a new rear housing.
Check out our transfer case upgrade as featured on Truck U TV on Speed Channel
Application table.
1500, 1500HD, 2500, 2500HD, 3500
NP246, NP261HD, NP263HD, NP261XHD, NP263XHD
NP246, NP149
1500, 2500
NP246, NP261, NP263, NP263HD
1500, 2500

FAQ - Transfer Case Pump Upgrade Kit

What do I do with the OEM anti rattle clip when installing this upgrade?
You can discard the factory clip during installation of this kit. Its been designed to work with the clip removed.

What other parts will I need to install this upgrade kit?
We tried to make the kit all inclusive for a basic installation. This is taking into consideration of course that its being installed as preventative measures. If its being installed as part of a repair or after pump rub has occured, there is no real way to know the extent of the damage inside the case until it is torn down. Most times, as long as the case has not run out of fluid, it can usually be repaired with a new rear housing and seal and prevented from ever happening again using the upgrade kit. Regardless of the reason for installing this upgrade, you will need to refill the transfer case with oil. We recommend our Performance Transfer Case Oil for use in ALL transfer cases.

Replace your stock drain plug with Magnetic Drain Plugs to catch small debris and help extend fluid life. Kit contains a Magnetic Drain plug and a new fill plug made out of a high strength corrosion resistant 304 Stainless Steel.
  • Promotes transfer case performance
  • Increases shifting performance
  • Dramatically reduces wear
  • Increases component efficiency
  • Blended specifically for use in GM transfer cases
  • May be used in GM, Ford and Chrysler transfer cases
  • For use in diesel or gas transfercase
  • Cost effective upgrade for Auto Track II
  • Performs in manual or electric shift applications
  • Reduces irritating drive shaft clunk
  • Increases drive line performance by reducing clutch chatter
  • Drastically reduces wear on internal components & seals
2 Quarts (64 fluid oz.) One Transfer Case will use 64 fluid oz.
 Average Rating:  5 Star Rating
 based on 31 Customer Reviews  
Write A Review
   Transfer case upgrade kit, December 6, 2019  By Anonymous (SIOUX CITY, IA)(Verified)
Love this kit. Third install. Great product.
   Transfer case parts and pump upgrade, August 6, 2019  By Anonymous (piney Flats, TN)(Verified)
You all are the best, ypu all are the real deal. I will always return to you. Learned my lesson from one of you competitor.
   Nice Kit, June 11, 2019  By Michael (Navasota, TX)(Verified)
Really nice kit. Should keep my new case half from getting rubbed through like the original did. Installation was straightforward and the instructions were clear. All around a good product.
   Great Instructions, May 23, 2019  By Anonymous (Edmonton)(Verified)
The product seems as advertised. Huge balue in the written and pictured instructions. I have seen too many long cumbersome clunky ambiguous YouTube vids - so really appreciate these.

For my tcase (2006 model 246GM with 2.72 ratio) I needed to begin to separate the case halves about 3/4” and then open C-clip and move the shaft forward; more concurrently and less in a sequence as apparent in the instructions.

Not a product issue, but the C-clip does not have rings in the end to clasp with typical tool and couldn’t find a specialty tool on long weekend after 4, used regular tool with improvised ends via 2 small aluminum ‘crush type’ cable clamps to convert tool. Annoying, frustrating, time consuming - so depending on your toolbox, be prepared to chase down a decent tool.
   Quality, February 9, 2019  By Anonymous (KINGMAN, KS)(Verified)
Very good part. Will reccomend. Fixed my issue!
   Great service, December 18, 2018  By Anonymous (FORT COLLINS, CO)(Verified)
Part fit perfectly and they have a great video online showing installation instructions.
   Great parts fast shipping, November 13, 2018  By Anonymous (SOUTH LYON, MI)(Verified)
Fit perfect. Great directions.
   Second to none, November 5, 2018  By Anonymous (Healy, AK)(Verified)
Great product in a nice bundle with everything you need. Awesome video and instructions. Highly recommend if you have one of the affected transfer cases.
   PUMP Rub Upgrade kit, October 12, 2018  By Jarrett (STILLWATER, OK)(Verified)
The Pump Replacement Part worked great and the Oil Was amazing. However, the Gasket for the T case did not fit the Bolt Hole Pattern.
   Pump upgrade, September 2, 2018  By Anonymous (Arlington, TX)(Verified)
Overall Video was very good.
Some feedback. Replace the oring every time you remove the tube. Squirt some oil into the hole of the pump as a prelube before final install. Clean and inspect suction screen for damages replace if needed.
Leave the factory supplied magnet in place it’s surface is much larger then your drain plugs also grabs magnetic debris before entering the pump.
Compliment the system by using you magnetic plugs as added control of magnetic debris.
Supply new pump screws and a torque spec as there easily stripped not all transfer cases use Torx some use Phillip’s head screws.
Apply thread locker on case half bolts as well and don’t discard the cup type washers there used as a corrosion preventer.
Show damaged cases in the video so people understand what happens. Also show bad bearings verse new bearings, promote the use of new parts like seals and gaskets.
Also some transfer cases use a wave washer against the pump you want to show correct location if used.

Great products you have keep you the great work !
   Canadian customer, June 13, 2018  By Tom (Mitchell)(Verified)
Recieved this kit very quickly, I believe 3 business days. Over all its exactly as described. Great product and I appreciate MA's outstanding quality. One thing that bothered me was the additional 46 dollar brokerage fee upon delivery to my location. My fault for not being informed however, as I didn't look at their shipping details before making my purchase and it clearly states that there may be additional fees on international orders. If your a canadian buyer perhaps you might look into purchasing their product from an outside source with different shipping method to avoid these fees. Other than the additional cost I'm very pleased with both the product and speedy service of merchant automotive.
   The dreaded "PUMP RUB" got me, May 29, 2018  By Anonymous (Orland Hills, IL)(Verified)
I installed this in my Chevy 2500 HD too late to save the case, and tried using a different vendor for the case half. Unfortunately, the case half had a different size driveshaft output size and I had to do it twice, after buying the correct case from Merchant Auto. Don't do what I did, buy from Merchant and save the labor.
   Just do it!!, May 2, 2018  By Aaron (Buckley, WA)
Had 235k on the truck when I did my build. The transfer case was all original, no leaks but I bought the kit and transfer case half over the objection of the shop. When they got into it, the pump had rubbed nearly completely through. Glad I forced the issue.
   Excellent, April 27, 2018  By Anonymous (KIRKSVILLE, MO)(Verified)
Was impressed with quality of productthe transmission shop I had installed showed me what they use-(thin piece stamped)-not near the quality. They were
also impressed with quality annd fitment. Install was straight forward with no complications-good directions.
   Pump upgrade, April 7, 2018  By Anonymous (Medina, OH)(Verified)
Really nice product, quick shipping and quick help finding the right part.
   Potential problems solved!!!!, March 27, 2018  By Anonymous (KIRKSVILLE, MO)(Verified)
We got lucky as our 2006 LBZ only has 75,000 on it, and the spring clip was it place BUT, it had already started to wear a small spot. We installed the kit and
also installed the transfer case brace. Instruction were clear and easy to follow. We also put in new seals, one was a real turd, but we replaced them all, which
took a little longer that just the kit. The brace only took a few minutes when putting case back in. The mechanic that gave me a hand is a transmission 'guru'
and was impressed with both the hub kit and the brace. He thought they were excellent preventative measures and has seen several cases destroyed by the problems these two items prevent. Am very satisfied with these two products. The rear output bearing was in great shape so we did not need to use it,
   Best Pump rub kit out, March 20, 2018  By Josh (Lacey, WA)
Got this quality kit 7 years ago. I've installed several since. This by far is the best kit on the market. Still in my truck to this day.
   Quality Product,, March 6, 2018  By Anonymous (Bradenton, FL)(Verified)
Quality Product, Product exceeds expectations. Simple to install with basic mechanical experience.
   Transfer case pump rub kit, February 25, 2018  By Anonymous (Edinburgh, IN)(Verified)
Excellent product !!!!
   Perfect!!, February 18, 2018  By Anonymous (GLENDORA, CA)(Verified)
You earned a customer for life! Kit was complete and as easy to install as they said it would be! So nice to find a company that delivers on its claims!
   I am an OG pump housing buyer, January 7, 2018  By John Tollison (DeFuniak Springs, FL)
This kit is nothing but fantastic, I bought my kit back in 2006 when they were just coming out, and the price was 275 bucks! Still money well spent. Well here I am 12 years later and still running the same case half with my epoxy patch and all is well! If you have not bought this kit, I can show you pictures of what I have encountered inside transfer cases.... do the pump housing, you will not regret it!
   Great product all around, October 27, 2017  By Anonymous (Gray, ME)(Verified)
Just did my 263 @ 150k. Thankfully it was still in great shape. Great product, and instructions. Very easy. Only thing i'd add to the instructions is to clean the magnet below the oil pickup before reassembly.
   Complete kit, October 19, 2017  By Daniel (Conway, AR)(Verified)
Great product and easy to install. I love that it comes with everything you need to complete the job.
   Rub Kit, September 20, 2017  By James (BALSAM LAKE, WI)(Verified)
Product is everything as advertised,came in a timely fashion, only thing I would add to the directions is to lube the pump plates before you reinstall with grease or transmission fluid.
   pump rub, September 7, 2017  By Anonymous (PAYSON, AZ)(Verified)
Quality product and easy to follow instructions.
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