Replaces the sticking factory thermal bypass in the GM 6L80 cooler circuit so full ATF flow reaches the cooler from the first mile.
Running hot trans temps while towing a camper, pulling a trailer up grade, or idling a Tahoe in summer traffic? On 2014-2018 GM half-ton trucks and SUVs with the 6L80, the part that decides whether fluid ever reaches the cooler is the thermal bypass valve in the cooler line circuit, and when it sticks the transmission cooks with the cooler sitting cold. This is the Pacific Performance Engineering (PPE) 125068000, a billet aluminum replacement for that factory valve on Silverado 1500, Sierra 1500, Tahoe, Suburban, Yukon, Yukon XL and Escalade models.
Fluid leaving the 6L80 for the radiator cooler passes through the thermal bypass valve first. When the ATF is cold, a wax-type thermostatic element keeps the valve in bypass so fluid circulates straight back to the transmission and warms up quickly. As the fluid heats, the element pushes the valve open and routes ATF through the cooler. GM's own TechLink notes the original valve on these trucks did not fully open until about 194 F (90 C), and GM later released an updated valve that fully opens around 158 F (70 C). If either valve fails closed from a worn element or debris, the cooler is effectively out of the loop. PPE's billet valve replaces the restrictive factory internals with open passages so fluid flows to and from the cooler all the time, and it adds a service plug with a neodymium magnet to catch ferrous wear particles.
Watch transmission temperature with a scan tool on a warm drive. If temps keep rising while the cooler inlet and outlet lines stay at very different temperatures, the bypass is suspect. Also rule out low fluid, a restricted cooler and a slipping converter clutch. Our 6L80 common problems guide covers converter shudder and heat-related clutch wear, and the 6L80 Escalade shift problems guide walks through harsh and delayed shift diagnosis on the same GMT K2XX platform.
PPE lists the 125068000 for 2014-2018 GM 6L80 six-speed applications with the 4.3L, 5.3L and 6.2L: Silverado 1500, Sierra 1500, Tahoe, Suburban, Yukon, Yukon XL and Escalade. GM cross-references are 13511136 and 85585333. The critical check is the cooler line connection at the valve. This version is for trucks with the plate-and-bolt style line retainer. It is not compatible with quick-connect fittings and clip-style retainers, which some 2014-2015 trucks use, and PPE sells a separate quick-connect part for those. Look at your lines before ordering, or send us your year and VIN and we will confirm. Everything else we stock for this transmission is on the 6L80 parts page.
If heat has already done damage and the truck shifts harshly or flares, the valve body is often next on the list; a 6L80 valve body reprogramming kit with TCC valve addresses pressure regulator and converter clutch wear while the pan is down.
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Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
Only if your cooler lines attach with a plate-and-bolt retainer. Some 2014-2015 trucks use quick-connect fittings with clip retainers, and this valve is not compatible with those. Check the line connection at the valve or send us your year and VIN.
No. It replaces the thermostatic factory valve with open passages, so fluid flows through the cooler all the time instead of waiting for the element to open.
PPE cross-references it to GM 13511136 and 85585333.
PPE specifies two of its compound washers, part 114052004, in place of the factory seal 85628205. They are sold separately. You will also need Dexron VI to top off the fluid.
No programming is involved. It is a mechanical part in the cooler line circuit. Check the fluid level hot after installing.
It traps ferrous wear particles in the cooler circuit. Pull and clean it at fluid services and use what it collects as an early warning of internal wear.
