6L80 Reaction Shell, new and ready to install. Fits the 6L80. Ships fast from the USA.
If your 6L80 or 6L90 has come in with burnt clutches, a converter clutch that slips at cruise, harsh or flared shifts, or codes like P0741, P0742 or P0218, the root cause is usually worn bores in the valve body and pump, not one bad hard part. This listing is the Sonnax Sure Cure kit, part number SC-6L80-6L90, the multi-piece reconditioning kit in our photo. To be clear up front: despite the listing name, this is not a planetary reaction shell. It is a valve body and pump repair package for rebuilders working on 2006-2020 Silverado, Sierra, Tahoe, Suburban, Yukon, Escalade, Camaro and Corvette units.
The 6L80 is controlled entirely by oil pressure that the pump creates and the valve body meters. When the aluminum bores around the pressure regulator, TCC regulator, converter feed limit and actuator feed limit valves wear oval, oil leaks past the spools. Line pressure goes erratic, cooler and lube flow drop, the converter clutch cannot hold, and the clutch packs apply soft or late until they burn. Sonnax describes the cause as loss of oil pressure from worn components in critical oil circuits, and lube-related failure. The kit puts oversized valves, end plugs and a bushing back into those circuits so pressure is controlled where GM intended.
Per Sonnax, the kit contains:
Before you open the unit, put a gauge on the line pressure port and compare actual pressure to what the module is commanding. Pressure that wanders or will not follow the command points at the pump and valve body bores this kit addresses. Sonnax also publishes a vacuum test procedure for the actuator feed limit bore. Our 6L80 Camaro shift problems guide walks through that pressure test and the cold 2-3 flare that is caused by trapped air rather than wear, and the 6L80 common problems guide separates hydraulic faults from module and sensor faults.
Sonnax lists SC-6L80-6L90 for the GM 6L80 and 6L90. The listing does not split the kit by year, and 6L80 valve bodies did change over the production run, so identify your valve body before you start. Sonnax notes the instructions show the newer 104520-16K pressure regulator valve, while the earlier kit with valve 104520-07K required drilling the pump. If you are unsure what you have, send us your year and VIN, and browse the rest of our 6L80 parts for anything else the rebuild needs.
This is shop work, not a pan-drop fix. The valve body and pump come apart on the bench, and Sonnax calls for its own tooling to ream the worn bores: F-104520-TL11C, F-104740-TL12, F-104740-TL7, F-104520-TL7C, the VB-06 oversized pump base plate and the VB-FIX fixture. Sonnax also warns that the stator support bushing must be pressed with an arbor press; a hydraulic press or a driver and hammer can distort it. Clean every bore, follow the supplied guide in order, and refill with Dexron VI only.
Since the kit usually goes in during a full overhaul, pair it with a 6L80 master rebuild kit with frictions, gaskets and filter. If the old unit burned clutches, the cooler is full of debris, so flush it or replace it with a 6L80 transmission cooler before the rebuilt unit goes back in.
| Fits | 6L80 |
| Part type | Reaction Shell |
| Condition | New |
| Brand | Sonnax |
| Ships | From the USA |
| Warranty | 1-year |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
No. The listing name is wrong. The part shipped is the Sonnax Sure Cure kit SC-6L80-6L90, a valve body and pump reconditioning kit, as shown in the photo. If you need a planetary reaction shell, contact us with your year and VIN before ordering.
It targets the usual causes. Sonnax lists high TCC slip RPM, P0741, P0742, P0218, low cooler flow and overheating among the symptoms the kit addresses through the oversized TCC regulator, converter feed limit and pressure regulator valves. A converter that is already damaged still needs to be replaced.
Sonnax says this version uses the newer 104520-16K pressure regulator valve. The earlier kit with valve 104520-07K was the one that required pump drilling, so follow the instructions that match the valve in your box.
Sonnax lists reamer tooling F-104520-TL11C, F-104740-TL12, F-104740-TL7 and F-104520-TL7C, the VB-06 oversized pump base plate and the VB-FIX fixture, plus an arbor press for the stator support bushing.
Yes. Sonnax lists the kit for both the 6L80 and 6L90. The 6L45 and 6L50 are not listed for this kit.
Dexron VI. Do not mix in universal or multi-vehicle fluids after a valve body repair.
