10L90 Identification Guide: RPO Codes, Generations and Crate Units

A 10L90 and a 10L80 look like the same transmission on a lift. Same family, same DEXRON ULV, same pan, same filter kit, same fluid change volume. The difference is what GM rated them to carry and which cars they went into, and none of that is stamped where you can read it with the pan still on. Order off "it's a 10-speed" and you will guess wrong sooner or later.

This is the order I identify one in: RPO first, then the physical checks that rule out the rest of the family, then valve body generation, then recall exposure, then the electronics that tie the unit to its own TCM. Specs and part numbers come from GM, NHTSA, ATRA and Sonnax, listed at the bottom. Where something is my own bench habit, I say so.

Recommended 10L90 parts

Once you know it is a 10L90 and which valve body it has, these fit the whole 10L60/10L80/10L90 family: valve body repair parts, the 24294355 filter and pan gasket kit, and DEXRON ULV. Ships from the USA, secure checkout.

Sonnax 10R80/10R90 Zip Kit Ford GM 10-Speed Valve Body

$259.99View part

10L60/10L80/10L90 Transmission Filter and Pan Gasket Kit

$30.99View part

ACDelco Dexron ULV ATF for GM 10-Speed Automatics, 1 Quart

$17.99View part

Step 1: read the RPO, not the badge on the trunk

ATRA's GEARS magazine gives the fastest route: find the QR label on the driver's door B pillar and scan it with a phone app to display the build information. That label lists the RPO codes for that VIN, and the transmission RPO is the identification. Everything else in this guide is confirmation.

GM has published three 10L90 RPOs that I can source directly:

Look at the CT5 row in that same GM chart and you see why the badge is useless. The 2025 CT5 lists three different 10-speeds: a 10L60 (MQ2), a 10L80 (MHS) and the 10L90 (MHX). The Escalade lists a 10L80 (MHS) and the 10L90 (MHO). "It's a CT5" narrows it to a family. The RPO narrows it to a unit.

Step 2: the physical checks, and the one that does not work

Fluid volume will not separate a 10L90 from a 10L80

On a lot of families the drain pan is a decent tell. Not here. GM's 2025 chart lists every 10L60, 10L80 and 10L90 row at 7.7 liters (8.1 quarts) of DEXRON ULV for a fluid change. The only family member that stands out is the 10L1000, which the same chart lists at 13.6 liters (14.4 quarts). If you caught fourteen quarts, it is not a 10L90. If you caught eight, it could be any of the other three.

The Chevrolet Performance 10L90 instructions give the full set of numbers, which are worth having on the ticket:

GM is explicit about fluid: DEXRON ULV only, and the instructions say in plain words not to use DEXRON VI or DEXRON HP. They also say to shake the quart bottles before pouring to stir up the additives, which is the first time I have seen that printed in an OEM fill procedure.

What the 10L90 actually is on paper

GM's own description of the 10L90 in the Supermatic instructions is the cleanest spec sheet I have found:

• Torque rating: 650 lb-ft. This is the number that makes it a 10L90.
• Weight: about 107.6 kg (237.19 lb).
• Architecture: four simple planetary gearsets, two brake clutches and four rotating clutches, six clutches in all, delivering 10 forward ratios and reverse. The four rotating clutches sit forward of the gearsets to shorten the oil feeds.
• Case: integral bell housing, no separate bell.
• Pump: off-axis, gear-driven variable vane pump packaged low in the unit, located in the valve body itself.
• Converter: four-element with a pressure plate splined to the turbine.
• No dipstick and no fill tube. Level is set through a case plug, which is a quick visual cue that you are looking at the GM 10-speed and not an older six-speed.

GM's published ratios for the 10L90:

That works out to a 7.38 overall spread, 7th is direct, and 8th through 10th are overdrives. Useful when a scan tool shows a commanded gear and you want to sanity-check the input and output speeds against it.

Tailhousing is not a reliable tell

GM builds the Supermatic 10L90 crate unit from the Camaro transmission but fits it with the slip yoke rear housing from a 2018 Tahoe (RPO MF6). That tells you rear housings move between applications inside this family. Do not identify a loose unit by its extension housing, and do not assume a car-style or truck-style tail means a car or truck guts.

Step 3: Gen 1 or Gen 2 valve body

Sonnax catalogs the 10L90 as two separate units, 10L90 (Gen. 1) and 10L90 (Gen. 2), because the valve bodies take different parts. This is the step that decides whether the kit on the shelf fits.

• Gen 1 uses latch valves in the clutch control circuits. Sonnax's latch valve stem repair kit for it is 105740-47K.
• Gen 2 drops the latch valves and controls clutch feed through a feed limit low and a feed limit high valve, with check balls in line. Sonnax's drop-in kits are 105740-54K (low) and 105740-58K (high). Sonnax's Gen 2 symptom filter lists conditions the Gen 1 page does not, including 5th gear only and code P0747, which lines up with the recall behavior below.

On the bench the difference is obvious once the body is off: look for latch valve trains versus the feed limit valves. If a customer has a parts receipt, the valve body service part number settles it faster.

There is also a Gen 3 service valve body, released June 19, 2025, under 24071206 (3.0L diesel) and 24071207 (5.3L and 6.2L gas). Sonnax says both fit only ETRS trucks with electronic park control. The quickest visual ID is that the TCC solenoid moved to the case side of the body, the lower casting is gone, and the default disable solenoid mounts to the lower cover plate. It is a truck part. Do not order one for a Camaro or CT5 10L90 without confirming fitment by VIN.

Step 4: is this unit inside recall 25V-148?

GM's Part 573 filing for recall 25V-148 (GM N242480630) covers 90,081 cars with the 10-speed:

• 2020–2022 Chevrolet Camaro, built April 15, 2019 to June 28, 2022 (50,147 vehicles)
• 2020–2021 Cadillac CT5, built May 29, 2019 to December 22, 2021 (27,097)
• 2019–2020 Cadillac CT6, built June 26, 2018 to January 24, 2020 (10,602)
• 2020–2021 Cadillac CT4, built September 11, 2019 to December 22, 2021 (2,235)

The filing names the cause as excessive wear in the control valve body causing a fluid leak and a pressure drop that makes certain valves move unexpectedly. Drivers notice harsh shifting, and in rare cases the wheels lock up momentarily, under 150 milliseconds per GM. The recall covers the 10-speed in those cars regardless of which 10L it is, so the RPO does not get a car out of it; the VIN does.

The part that matters for identification: the filing lists the recalled control valve body part numbers as 24049466, 24043769, 24047993, 24049469 and 24047995 (plus one entry printed as 2403771, which appears to be a truncated number). If the body in your hands carries one of those, you know its history before you vacuum test a single bore. Run the VIN through GM or NHTSA before any paid work on one of these cars.

Step 5: the unit is married to its TCM

This is the identification step people skip and then pay for. GM's Supermatic instructions put it in capital letters: each controller is matched to its transmission, and each solenoid inside the transmission is characterized, with that data loaded into the controller. Swap a TCM between two 10L90s without programming and the new one is running another unit's solenoid data.

GEARS adds the service-side version: the linear pintle solenoids are not available separately. If one is sticking, or the LPC accumulator bore or a linear pintle bore is worn, you order a valve body and program its Part Unique Number (PUN) or Mechanical Characterization and Virtual Matching (MCVM) data. Write down the characterization number on the body you pull; that is part of the unit's identity.

Step 6: is it a crate Supermatic?

Swap cars with an LT1 or LT4 and a 10-speed are showing up at shops now, and the transmission in them is often the Chevrolet Performance Supermatic 10L90. The IDs:

• Transmission 24045004, sold in kit 19420480 (LT4) or 19432851 (LT1). The kits include the transmission, harness, a pre-flashed TCM, vent tube and cooler line adapter with -6 AN fittings.
• Two calibrations, Normal and Sport, selected with a PRNDX shifter. There is no L range or extra detent below X; tap shifting is optional.
• With a Chevrolet Performance engine control kit and aftermarket gauges, GM notes the ECM may not display gears 9 and 10 even though the transmission uses all ten. That is not a fault.

GM is clear that this unit is not a service replacement for a production vehicle and will not operate correctly in one. For internal service parts, GM says to reference the 2017–2021 Camaro 10L90, RPO MI4. That line is worth knowing: it means a crate 10L90 is a Camaro unit inside, and you order its soft parts that way.

Step 7: check the level the way GM wrote it

Once you know what it is, set the fluid level correctly before you judge anything about how it shifts. From the GM 10L90 procedure:

1. Engine running, in Park, vehicle level. Fluid temperature (TFT) between 75 and 80°C (167–176°F). The unit has an internal thermal bypass, so do not check below 70°C.
2. Move through each range with a pause of at least 3 seconds, back to Park, idle at least a minute at 500–800 rpm.
3. Pull the case plug with the engine running. If it streams, wait for a drip. If nothing comes out, add until it streams and then drips.
4. Reinstall the case plug at 22 Nm (16 lb-ft).

GM warns that checking above 80°C leaves it underfilled and below 75°C leaves it overfilled, and that overfill can push fluid out the vent. If you need heat, GM allows brake-torque stalls of 10 seconds on and 10 seconds off, never above 1,500 rpm.

The job ticket version

• RPO from the B-pillar QR label. MI4 (2017–2021 Camaro), MHX (CT5), MHO (Escalade/ESV) are GM-published 10L90 codes.
• Family check: 7.7 L fluid change does not separate it from a 10L80; 13.6 L means 10L1000.
• Generation: latch valves = Gen 1; feed limit low/high valves = Gen 2. Gen 3 (24071206/24071207) is an ETRS truck service body.
• Recall: VIN check for 25V-148 on 2020–2022 Camaro, 2020–2021 CT4/CT5, 2019–2020 CT6. Note the valve body part number.
• Electronics: record the solenoid characterization / PUN data; never swap a TCM without programming.
• Crate unit: 24045004 in kit 19420480 or 19432851; service it as a Camaro MI4.
• Fluid: DEXRON ULV only, level set hot at 75–80°C, case plug 22 Nm.

FAQ

How do I tell if I have a 10L80 or a 10L90?

Read the RPO code off the QR label on the driver's door B pillar. Fluid capacity will not help, because GM's 2025 capacities chart lists both units at 7.7 liters, 8.1 quarts, of DEXRON ULV for a fluid change, and both use the same 24294355 filter and pan gasket kit. What GM rates differently is torque capacity, 650 lb-ft for the 10L90, and that is not something you can see from under the car. The door label, or a GM parts lookup by VIN, is the answer.

What RPO code is a GM 10L90?

GM has published at least three. Chevrolet Performance says its Supermatic 10L90 is based on the 2017-2021 Camaro unit, RPO MI4. GM's 2025 Transmission Capacities and Fluids chart lists the 10L90 as RPO MHX in the CT5 and RPO MHO in the Escalade and ESV. The same chart lists a 10L60 and a 10L80 in the CT5 too, so the model name alone does not tell you which unit you have.

How much fluid does a 10L90 hold?

Per the Chevrolet Performance 10L90 instructions, a pan and filter service takes about 7.7 liters (8.1 quarts), an overhaul takes about 10.95 liters (11.6 quarts) for the transmission alone, and the complete system including the cooler is about 12.52 liters (13.23 quarts). The only fluid GM allows is DEXRON ULV. DEXRON VI and DEXRON HP are specifically called out as wrong.

Is my 10L90 part of the GM 10-speed recall?

Check the VIN. NHTSA recall 25V-148, GM number N242480630, covers 90,081 vehicles with the 10-speed: 2020-2022 Camaro, 2020-2021 CT4 and CT5, and 2019-2020 CT6. The filing lists the recalled control valve body part numbers, and the cause is valve body wear that can drop pressure, cause harsh shifts and in rare cases a momentary wheel lock-up. Vehicles outside those build dates and valve bodies are not in it.

Can a Chevrolet Performance Supermatic 10L90 be used as a service replacement?

No. GM states on the first page of the instructions that the Supermatic 10L90 (transmission 24045004, in kits 19420480 and 19432851) is not a service replacement for any production vehicle. Its TCM carries a crate-engine calibration matched to that transmission's characterized solenoids and only works with a Chevrolet Performance LT engine control system. For service parts inside it, GM says to reference the 2017-2021 Camaro 10L90, RPO MI4.