10L90 Overhaul Kit 2018-2024

This is a gasket set with sealing rings and seals for the GM 10L90, sold under maker part 105002 and cross-referenced to the KP33900PX overhaul kit. It suits a 10L90 out of a 2018 or 2019 Camaro, Cadillac CT6 or other high-output GM application that is already on the bench, with clutches that measure good but circuits that leak. The usual reasons for a reseal are slow engagement, shifts that soften as the car heats up, and fluid on the garage floor. One thing up front: the listing title reads 2018-2024, but the kit maker rates it for 2018-2019 ten-speeds only. The fitment section explains what that means for your car.

What a gasket and ring set does in a 10L90

The 10L90 meters every clutch apply through its valve body, where six linear solenoids control the shift clutches and separate solenoids handle line pressure and converter lockup. Once the valve body sets a pressure, the oil still has to get through the case passages, past the case-to-valve-body gaskets, and into the spinning shafts and drums through sealing rings before it reaches a piston. If a ring wears thin or a gasket takes a set, some of that metered pressure never makes it to the clutch, and the precise pressure control the 10L90 depends on stops working. This set renews the rings, gaskets and seals, which brings every circuit back to the pressure the solenoid commands.

Symptoms a reseal addresses

• Delayed engagement, especially into Reverse, before the fluid is warm
• Shifts that are crisp when cold but go soft or slip after a hard drive
• Line pressure that tests low at a port while the pressure control solenoid checks good
• Leaks at the pan, case seams, cooler line fittings or output shaft
• Drums that hiss or fail to hold during an air check

How to confirm the leak is internal

Electrical faults cause many of the same complaints, so check the circuits first. The 10L80 and 10L90 shift solenoid guide covers solenoid testing, and the speed sensor symptoms guide explains why a bad sensor signal can look like slipping. Valve body bores also wear. Sonnax publishes a Generation 1 vacuum test guide for these valve bodies that lists, bore by bore, which complaint each worn valve causes. If the bores pass and you still have low pressure, the leak is in the rings and gaskets this set replaces.

Fitment

The kit maker lists part 105002 for GM 10L80 and 10L90 transmissions and states 2018-2019 only, which covers the Generation 1 period before GM moved to Generation 2 valve bodies around late 2019. A 2020-or-newer 10L90 should not be ordered with this set until the unit has been identified. Scan the RPO QR label on the driver door B-pillar, or send us your year and VIN and we will confirm it before shipping. For a 2017 build or a car you have not identified yet, compare the 10L90 overhaul kit for 2017-2022. Hard parts and tools for this transmission family are on the 10L80 and 10L90 parts page.

Install notes

• The set contains gaskets, rings and seals only. Frictions, steels and pistons are not included, so price a 10L90 clutch module in case the clutches are glazed when you open the unit.
• Replace the solenoids while the valve body is off if they are high-mileage. The 10L90 solenoid kit covers the set.
• Lubricate each sealing ring with assembly gel and let it size down in its groove before you slide the mating drum over it. A ring that rolls or cuts will leak from the first drive.
• Soak the lip seals in clean fluid, then air check every clutch through its feed hole before the unit goes into the car.
• Refill with Dexron ULV, set the level at operating temperature by GM's check procedure, and run the fast learn after clearing the old adaptive values.

The title says 2018-2024. Will it fit my 2022 car?

The kit maker rates part 105002 for 2018-2019 units only. A 2022 car is probably a Generation 2 unit, so send us your VIN before ordering and we will point you to the right kit.

How does this compare with KP33900PX?

Part 105002 is cross-referenced to KP33900PX. Both are gasket and seal sets for the 10L80 and 10L90, but they carry different year notes, so go by your unit's build year.

Does it include clutches or pistons?

No. It includes gaskets, sealing rings and seals. Frictions, steels and pistons are bought separately when your unit needs them.

Can I use it on a 10L80 too?

Yes. The maker lists it for both the 10L80 and the 10L90 within the 2018-2019 window.

What has to be done after the rebuild?

Fill with Dexron ULV, check the level hot, clear the adaptive values and run the fast learn with a scan tool so the TCM learns the fresh clutches.

• 10L80 Shift Solenoid Symptoms, Testing and Replacement
• 10L80 Input/Output Speed Sensor Symptoms
• 10L80 Valve Body Symptoms and Testing
• 10L80 Pressure Control (EPC) Solenoid Symptoms