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Description
Merchant Automotive 10001 Transfer Case Pump Upgrade KitThe Merchant Automotive 10001 Transfer Case Pump Upgrade Kit for your 01 07 GM 6. 6L Duramax is the best upgrade you can make to your GM transfer case (model 136, 146, 246, 261, 261HD, 263HD, 263XHD, 261XHD) to 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
The Merchant Automotive 10001 Transfer Case Pump Upgrade Kit for your 01-07 GM 6.6L Duramax is the best upgrade you can make to your GM transfer case (model 136, 146, 246, 261, 261HD, 263HD, 263XHD, 261XHD) to 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 therefore 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.With installation of this kit, you will have a LIMITED LIFETIME WARRANTY against pump rub.
Included Components:
- Merchant Automotive billet transfer case pump housing
- Transfer case adapter gasket at trans
- RTV Silicone
- Blue Threadlock
- Merchant Automotive sticker
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.
|
Application Guide |
||
|
Year |
Model |
Transfer Case Model Number |
|
1998-2007 |
GM Silverado/Sierra - 1500, 1500HD, 2500, 2500HD, 3500 |
NP246, NP261HD, NP263HD, NP261XHD, NP263XHD |
|
1998-2003 |
Blazer / Jimmy |
NP236 |
|
1999-2005 |
Astro/Safari |
NP136 |
|
1999-2007 |
Escalade |
NP246, NP149 |
|
2002-2007 |
Avalanche 1500/2500 |
NP246, NP261, NP263, NP263HD |
|
1998-2007 |
Suburban/Yukon/Tahoe/Yukon XL 1500/2500 |
NP246 |
Frequently Asked Questions:
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 occurred, 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.
WARRANTY INFO:
Lifetime
Shipping Notes
- Free Standard Shipping on $100+ Orders to the USA.
- Except Preorder products are shipped in 48 hours.
- Delivery to the USA:
- Standard Shipping : 3-10 business days
- If time is of the essence, please consider selecting expedited delivery for faster service.
Exchange/Return Notes
- We offer a 30-day return/exchange service after receiving.
- Final sale items are not eligible for returns or exchanges.
- To process your return/exchange, please contact us at [email protected]
- Please click here for more details>>> Return & Exchange Policy
4.0 ★★★★★
Based on 1572 reviews
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Product Reviews
★★★★★ 5
Cute and comfortable
Size: Medium, Color: Dark Colors
Super cute and comfortable.
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Reviewed in the United States on March 10, 2026
★★★★★ 3
Updated 7/25
Size: XX-Large, Color: Dark Colors
Not too long, not too short in the bum where you have a wedgie allll day long.
I've tried soooooo many brands (Amazon probably hates my guts) but I've been searching for months to find some long enough to go over that crease between your thigh and groin. Mine gets soooooo sweaty and then itchy so I needed something to cover and absorb.
The larger recommended size settled into my stomach/belly button area and makes it looks like I have the hugest fupa ever!
I
But like several reviewers before me mentioned-you might as well toss the grey pair. Its like 1-2 sizes too small. Just the grey one! ALWAYS! So I knew to try it on so I wasn't shocked later!
Wish they had and all black set (hint, hint), without that weird, bad fitting grey pair. Just get rid of that one!
Update 1: they do run big.
And yes, liners/pads DO stick. Thank goodness.
Update 2: bought 2 sizes smaller than Amazon recommended. Tight when tried on, much better after washing. Very stretchy.
Now it's wedgie problem. All day, all the time wedgie. Not good.
No one gets that women have butt's that are bigger than the front. So yes, it goes just below my belly button, but the backside barely reaches to the bottom on my tail bone/start of the booty crack.
So now my search moves to men's boxer briefs....
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Reviewed in the United States on June 25, 2024
★★★★★ 5
Love
Size: X-Large, Color: Black
My favorite! They are so comfy I’ve bought 2 times
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Reviewed in the United States on March 9, 2026
★★★★★ 2
Six seams come together between your vag and rear exit. Not good.
I thought these were cute and liked the colors. They were on sale. I was looking for regular cotton boy shorts for women. I am very petite. For some reason it has become very difficult to find regular cotton boy shorts that have a gusset and the elastic band is covered. I do mean that I was just looking for basic cotton slip shorts that I have bought within the last year that have a covered waistband because I get irritation from elastic. Because of the weird data silos that Walmart and other retailers are now using, my purchase history will not pull up underwear purchases in the last year so that I may be able to reorder the ones I liked. I am so frustrated by this but needed to buy more underwear. I saw that the elastic was not covered but thought I'd try them anyway at the sale price because this elastic band is the type that can be folded over if irritation occurs. However, this is the worst fit of underwear I've put on in a while. They are made for a woman with large thighs or rear. There is a gap at the leg holes giving the feeling of breeze/no security at the butt and there is nothing, no tension there, to stop these underwear from going right up and what makes it worse is they must have made these for a woman with orifices right at the front of her pelvis. When you look straight down into the underwear you will see where the crotch gusset ends and the back seam begins. It is straight down! In other words the gusset ends and the left to right leg seam plus the seam going to the back ALL meet at this intersection which is right on top of my back door opening. This problem plus the fact that the leg holes are too big and nothing is holding the underwear down snug around my thighs means the most uncomfortable underwear seam JUNCTION is also going to be riding up my backside. I hate them. Cute colors but these underwear are not for people like myself who I thought was pretty normal despite being petite. I just hate them and I find it really frustrating that I'm going to have to end up sewing my own underwear, which is is a very basic style of underwear, not because they are no longer being made but because Google searches and Amazon searches are so confabulated and leveraged that I can't find them no matter how hard I try. I'm sick of this. I'm absolutely sick of this and UNDERWEAR IS IMPORTANT. I give two stars because they colors are really cute but I hate them and need to put an extra gusset in and try to take up the leg holes.
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Reviewed in the United States on March 12, 2025
★★★★★ 5
comfy
Size: Large, Color: Organic Cotton 2 (5 Black)
I really like these organic cotton undies. they fit well and are very comfortable.
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Reviewed in the United States on March 18, 2026