Threads into the GM ATF fill port so you can push fluid in from a top-side exchanger on 6L80, 8L90 and 10L80 transmissions during a refill or fluid service.
Owners of a Silverado, Sierra, Tahoe, Yukon, Suburban, Escalade or Camaro with a GM six, eight or ten speed automatic quickly learn there is no dipstick to pour fluid into. After a pan drop, a cooler line repair or a valve body job, the fluid has to go back in through a threaded port, and squeezing a bottle under the truck while you hold a hose in a tight spot is messy and slow. This aluminum adapter threads into that port and gives you a 2 inch outlet that couples to a fill pump or a top-side ATF exchange machine, so you can put fluid in under control and stop when the level is right.
GM's owner manuals for 6L80 vehicles state there is no transmission dipstick and that checking and changing the fluid follows a special procedure; on the 2012 Camaro, GM lists Dexron VI and a 6.3 L (6.7 qt) capacity. The level is set at the check plug with the engine running and the fluid at the specified temperature. That means fluid has to be added through a port while you watch for the overflow, which is exactly what this adapter makes easy. You pump from below, the adapter seals against its shoulder so nothing weeps around the threads, and when the level is set you remove it and reinstall the factory plug.
A low or burnt fluid condition can mimic a hard-parts failure. Our 6L80 common problems and fixes guide explains how fluid breakdown shows up as shudder and harsh shifts, and the 6L80 Camaro shift problems guide covers the pressure test and the adapt reset that should follow any service. If the fluid smells burnt or has debris in the pan, a refill is only part of the fix.
The adapter is listed for the GM 6L50, 6L80, 6L90, 8L45, 8L90, 10L60, 10L80 and 10L90 rear-drive automatics, and for 2015 and later Chevrolet, GMC and Cadillac models using them. Because it uses the factory fill thread, it also suits earlier 6L80 trucks with the same port, but compare thread and seal to your plug before you rely on it. Fluid is where these units differ. GM's 2025 fluid capacity chart lists Dexron VI for the 6L90 with about 5.7 L (6.0 qt) for a fluid change, Dexron HP for the 8L80 and 8L90 at 7.0 L (7.4 qt), and Dexron ULV for the 10L80 at 7.7 L (8.1 qt). Put the wrong fluid in through a convenient adapter and you have created a new problem. Send us the year and VIN if you are unsure what your truck has, and find parts on our 6L80 transmission parts page.
Park level, clean around the plug, and remove it. Thread the adapter in by hand until the shoulder seats; do not crank on it with a wrench. Couple the 2 inch end to your pump or exchanger, add the correct fluid, then start the engine and cycle through the gears. Bring the fluid to the temperature in your service information, and when fluid runs out of the port in a thin stream the level is set. Remove the adapter and reinstall the plug. Pair it with a 3 liter manual ATF fill pump if you do not own an exchanger, and with a 6L80 oil pan with drain plug and filter if you want easier drains next time.
| Fitment | GM 6L50, 6L80, 6L90, 8L45, 8L90, 10L60, 10L80, 10L90 |
| Vehicles | 2015+ Chevrolet, GMC, Cadillac |
| Outlet | Universal 2-inch, mates to most ATF exchange machines |
| Material | Aluminum |
| Package size | 2.28 x 2.17 x 0.83 in |
It is listed for the GM 6L50, 6L80, 6L90, 8L45, 8L90, 10L60, 10L80 and 10L90 rear-drive automatics used in Chevrolet, GMC and Cadillac trucks, SUVs and cars.
Either. The 2 inch outlet couples to most top-side ATF exchange machines and to a manual fill pump hose.
It depends on the unit. GM lists Dexron VI for the 6L80 and 6L90, Dexron HP for the 8L80 and 8L90, and Dexron ULV for the 10L80. Confirm against your owner manual or send us the VIN.
With the engine running and the fluid at the specified temperature, fluid should drip from the check port. If none comes out, add more; if it pours, let it drain until it slows to a drip.
After a simple level correction it is usually not needed, but after a valve body, TEHCM or rebuild job, reset transmission adapts and complete a relearn drive.
