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Wehrli Custom Fabrication 17-19 L5P Duramax / 14-18 GM 1500 Transmission Cooler Thermostat Bypass Plug - WCF100469

  • CNC Machined Billet Aluminum Thermostatic Bypass Plug
  • Black Anodized Finish
  • High temperature silicone O-ring seals
  • Reduces fluid flow restriction to trans cooler
  • Simple Installation
  • Experience fluid temperature drops from 15-50 degrees F
  • Direct replacement of the failure prone OEM thermostat
  • Easy swap back to OEM setup for cold weather use
Availability: In Stock. Ships in 3-5 business days.
Pricing: $56.00


As a direct replacement for the failure prone OEM thermostat, the Transmission Cooler Thermostat Bypass Plug can drop fluid temperature from 15-50 degrees F by reducing fluid flow restriction to the trans cooler. In the stock application, we've seen the valve fail forcing trans fluid around the cooler in warm weather conditions that cause dangerous fluid temperatures for built and stock transmissions alike.

Recommended for trucks with stock or built transmissions and performing heavy towing in warm climates to help keep fluid temperatures in check.

The WCFab Transmission Cooler Thermostat Bypass Plug is a quick and easy install and will work with the following range of GM vehicles equipped with a factory installed transmission cooler thermostat bypass (6L80, 6L90, 8L90):

  • 2017-2019 Chevrolet Silverado & GMC Sierra 2500HD/3500HD with 6.6L Duramax Diesel
  • 2014-2018 Chevrolet Silverado & GMC Sierra 1500 with 4.3L 6 Cyl, 5.3L 8 Cyl, and 6.2L 8 Cyl Gas Engines
  • 2015-2020 Chevrolet Suburban, Tahoe & GMC Yukon with 5.3L 8 Cyl, and 6.2L 8 Cyl Gas Engines
  • 2015 Cadillac Escalade with 6.2L 8 Cyl Gas Engine




Shipping Information

  • Item Requires Shipping
  • 1.0 lbs.
  • W4.0000” x H4.0000” x L5.0000”

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