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10L80 Cooling: Demon3 Transmission Cooling Package has arrived

Demon3 Tow Package - Product Feature: PPE's Deep Transmission Pan, Cooler and bypass $799.97

128051110 PPE Deep Trans Pan 2019+ 3.0L Duramax $319.99

My favorite mods are the ones you can see all of the time and also provide a gain. The ability to now have an additional 4 quarts of transmission fluid in the system will help to increase the time it takes for the fluid to get hot while the 3/4" fins on the bottom will help to keep all of the fluid cooler during those long towing trips across the desert mid summer.

From :

PPE’s Heavy-Duty DEEP 10L80 Transmission Pan holds an extra 4 quarts of fluid and is cast from high-quality aluminum alloy for strength and optimal heat dissipation. Simply stated, more is always better when it comes to transmission fluid. Higher volumes of fluid take longer to heat up allowing for more stable transmission temperatures which help to extend transmission life.

Cast gussets provide strength and overall robustness. Internal heat sinks wick heat and acts as baffles to reduce fluid sloshing. External fins add surface area and use free-flowing air to radiate heat.

The PPE Heavy-Duty DEEP Aluminum Transmission Pan also features a high-power Neodymium magnet-equipped billet stainless steel drain plug to catch and hold harmful ferrous metal contaminants keeping them out of the transmission internals.


• Increases fluid capacity by 4 quarts which also lowers fluid temperature

• 3/4-inch external fins improve heat dissipation, lower transmission fluid temperature, and increase strength

• 5/8-inch internal baffles further improve heat dissipation and reduce the fluid sloshing effect

• High-power Neodymium magnet-equipped 304 stainless steel drain plug with Viton O-ring

• Tapped and plugged 1/8-inch NPT port for optional fluid temperature sensor

• Gussets provide extra support to the top flange and increases overall robustness

• Compatible with OEM gasket

• Limited lifetime warranty

124067000 10L80 Transmission Cooler $389.99

Direct replacement with no modifications required, count me in ! Significant gain in size makes it very clear why PPE saw a 45 degree decrease in transmission temperature with just this cooler installed.

From :

Boost your transmission a performance with this PPE Bar and Plate Transmission Fluid Cooler. Bigger effective cooling area and thicker core enables PPE cooler to draw 200% more heat from your transmission fluid compared to the factory cooler. We observed up to 45°F temperature drop with PPE cooler installed under the same operating conditions.

The PPE Bar and Plate Transmission Cooler is made of high-quality aluminum, with specially engineered fin construction to maximize cooling efficiency while maintaining pressure drop as low as possible. It is a direct replacement with no modification or additional parts needed. Reuse factory cooler hardware for installation.


  • 200% more heat dissipation

  • Direct replacement, back to factory mounting locations

  • High-quality aluminum bar and plate design

  • Limited time warranty

125069000 10L80 Thermal bypass valve $89.99

The factory bypass valve stays closed until 158 degrees and will then open to allow fluid to flow through the restrictive passages to the cooler. The PPE thermal bypass valve eliminates that valve and allows for full flow therefore allowing maximum fluid through the cooler when needed most.

From :

Add another measure of protection and increase fluid flow to the transmission cooler. Increase cooling capacity with this easy-to-install billet aluminum PPE Transmission Fluid Thermal Bypass Valve for the GM 10L80 10-Speed transmission.

The OEM part has restrictive internal passages. When the OEM valve fails in the open position, transmission fluid doesn’t reach your cooler. This can be caused by mechanical failure or debris. The result of stock valve failure can cause the transmission to dangerously overheat. Without properly cooled transmission fluid, the demands of towing and rigorous stop-and-go driving conditions shorten the life of transmission components. The PPE Bypass Valve eliminates the extremely restrictive mechanical factory valve, maximizing fluid flow to and from the transmission cooler.

For further protection, a Neodymium magnet equipped service plug with O-ring seal has been added. The removable plug traps ferrous debris and can be accessed to remove particles from the system. The factory bypass valve does not have this feature.


  • Maximizes fluid flow to and from the transmission cooler

  • Billet aluminum construction

  • Direct fit with OEM 10L80 10-speed transmission and fluid lines

  • Service plug with Neodymium magnet and O-ring seal

The Demon3 package- maximum transmission cooling

These are the big 3 items for maximum transmission cooling in the 3.0 LM2 Duramax diesel. If you are towing a lot or starting to see higher temps from the transmission, these are what we recommend, but we also suggest you do these modifications before increased wear is found.

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