Transmission Fluid Thermal Bypass Valve

Features:

• Fits 2017-2019 6.6L L5P Duramax.
• For Sierra/Silverado 2500HD/3500HD.
• Replaces factory transmission thermal bypass.
• Sends 100% fluid through coolers.
• Maximizes flow to transmission coolers.
• Helps prevent overheating if thermostat fails.
• Improved flow over factory valve.
• Billet aluminum body for durability.
• Neodymium magnet traps metal particles.
• Magnetic service plug is removable.
• Easy bolt-on installation.
• GM equivalent part 23413140.

Unlock Cooler Running Power For Your L5P Duramax Transmission

If you rely on your 2017-2019 Sierra or Silverado 2500HD or 3500HD to tow, haul, or put in long hours on the road, your transmission deserves better protection than the restrictive factory thermal bypass valve. The PPE 125065000 Transmission Fluid Thermal Bypass Valve is designed to keep fluid moving freely, sending 100 percent of your transmission fluid through the front-mounted coolers where it belongs. That added flow helps control temperatures when you are pulling a heavy trailer or creeping through traffic on a hot day. When the factory valve sticks closed, fluid can be blocked from the cooler and heat builds quickly. This upgrade eliminates that internal mechanical thermostat, removing a common failure point that can shorten transmission life. Additionally, the billet aluminum construction delivers strength and long term durability that stands up to real world abuse. It is a simple bolt-on upgrade that adds peace of mind every time you put your truck to work.

Engineered Flow Control And Added Protection In One Billet Upgrade

The PPE Thermal Bypass Valve replaces the factory unit with a precision machined billet aluminum housing that improves internal flow paths compared to the stock restrictive design. By directing all transmission fluid through the cooler circuit at all times, it maximizes heat dissipation and supports more consistent operating temperatures under load. This is especially important for the L5P Duramax paired with the Allison transmission, where heat management directly impacts clutch life and fluid condition. Furthermore, PPE integrates a Neodymium magnet equipped service plug that captures ferrous metal particles circulating in the fluid. The plug is removable, allowing you to inspect and clean collected debris during routine maintenance. The factory valve does not offer this added filtration feature, making this upgrade a functional improvement rather than just a replacement. With direct fit compatibility for 2017-2019 6.6L Duramax HD models and an easy installation process, it delivers measurable protection without complicated modifications.

Fitment: 2017, 2018, 2019 GM Sierra/Silverado 2500HD/3500HD 6.6L Duramax

Notes:

• Designed specifically for 2017-2019 L5P 6.6L Duramax HD models.
• Replaces factory thermal bypass valve prone to restriction.
• Eliminates internal thermostat style flow control.
• Ensures constant fluid flow through transmission coolers.
• Helps reduce risk of overheating from valve failure.
• Ideal for towing and heavy duty driving conditions.
• Includes magnetic service plug for debris inspection.
• Periodic magnet cleaning recommended during maintenance.
• Direct bolt-on replacement for OEM part 23413140.
• Professional installation recommended if unfamiliar with transmission service.

Install Instructions