6L90 valve body for 2006-2018, remanufactured and ready to install. Ships fast from the USA.
This is the valve body repair kit for owners and shops working on a 2006-2018 GM 6L90 in a Silverado or Sierra 2500/3500, Express or Savana van, Camaro ZL1 or Corvette Z06 and ZR1 that has started to shift harsh, flare between gears, slip the converter clutch or set pressure-related codes. It is a Sonnax Zip Kit, the 6L45-6L90-ZIP set of drop-in valves, sleeves, plugs and checkballs that you install while the valve body is apart. To be clear up front: this is not a complete valve body. If you want a bolt-in unit instead, see the sibling listings below.
The 6L90 has no bands; every gear comes from applying one clutch while releasing another, and the valve body regulates the oil for each of those clutches. Its aluminum bores wear as the steel valves move in them thousands of times, and its end plugs and checkballs eventually stop sealing. Each leak bleeds off a little pressure. Sonnax describes the kit as sealing those losses in the main line, clutch apply control, solenoid feed and lockup control circuits, plus several circuits known for end plug leaks and poor checkball sealing. That matters on a 6L90 because these units tow heavy loads, and lost apply pressure is how clutches start to burn.
Vacuum testing is the reliable way to find bore wear, and the kit includes the test nut for it. Sonnax publishes a vacuum test guide for the 6L45-6L90 family that lists the critical wear points and the symptoms each one causes. Check fluid level and condition and rule out the TEHCM first, since a failing control module can set similar codes. Our 6L90 valve body testing guide covers the process step by step, and 6L90 valve body wear and the bench fix explains which bores fail first.
This listing is for the GM 6L90 from 2006 through 2018. The kit itself is the same part used across the 6L45, 6L50, 6L80 and 6L90 valve bodies, but GM changed valve body castings and center supports over the years, so confirm your casting before you order or send us your year and VIN. Browse the rest of our parts for this transmission on the 6L90 parts page. If the bores are badly worn beyond what drop-in parts can seal, a remanufactured Sonnax 6L90 valve body is the better buy.
If the transmission has been slipping for a while, inspect the pump too; the 6L90 pump and our 6L90 common problems guide help you decide what else to replace while it is apart.
| Transmission | 6L90 |
| Year Range | 2006-2018 |
| Condition | Remanufactured / updated |
| Shipping | Ships from the USA |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
No. It is a repair kit of drop-in valves, sleeves, end plugs, seals and checkballs that you install in your existing valve body. For a bolt-in unit, look at our remanufactured or OEM 6L90 valve body listings.
The kit covers 2006-2018 6L90 valve bodies, which includes the HD Silverado and Sierra. Because castings changed over the years, confirm your valve body casting or send us your year and VIN before ordering.
No reaming or special tools are needed. You will want a clean bench, the valve body layout, a torque wrench in inch-pounds and a vacuum test setup to check your work.
It can if the cause is TCC regulator valve wear or lockup circuit leakage, which the kit addresses. A worn converter clutch or a TEHCM fault can set the same code, so diagnose before you buy.
Replace the filter, pan gasket and fluid with Dexron VI. If clutches are already burnt, a rebuild kit is needed, and a worn pump should be replaced.
Yes. Reset the transmission adapts with a scan tool and complete a relearn drive so the TCM learns the new clutch apply pressures.
