10L90 Transmission Rebuild & Repair in Glendale, AZ (GM)

Sun West Transmissions — Glendale, AZ. Free estimates, honest diagnosis and a 3-year / 40,000-mile warranty on qualifying rebuilds and replacements.

The 10L90: GM’s High-Torque Ten-Speed

The 10L90 is the higher-capacity version of GM’s ten-speed rear-wheel-drive automatic. It shares its basic design with the 10L80, which was co-developed with Ford, but it’s built to handle the torque of GM’s most powerful engines. GM introduced it in the late 2010s, first in high-performance models.

The 10L90 is best known as the automatic option in the supercharged Chevy Camaro ZL1, and it has also been used in other high-output GM applications, including certain Cadillac performance models. These cars are relatively rare compared to everyday trucks, which is why many owners have trouble finding a shop comfortable working on them. Sun West Transmissions in Glendale focuses on transmissions full time, and we can diagnose your car and perform a 10L90 transmission rebuild when it’s needed.

Built for Power, Sensitive to Abuse

The 10L90 is engineered for high torque and very quick shifts. It uses four planetary gear sets and six clutches, with a control module that can skip gears and make lightning-fast clutch-to-clutch shifts. In stock form and normal use, it’s a strong transmission.

Performance driving changes the equation. Repeated hard launches, track days, aggressive tuning and added power all increase heat and clutch load. In Arizona, where ambient temperatures can top 110 degrees, a spirited drive on a summer afternoon can push fluid temperatures much higher than in milder climates.

Common 10L90 Concerns

Shift Quality and Calibration

Harsh, abrupt or inconsistent shifts can be caused by calibration, adaptive learning, or the effects of an engine or transmission tune. In some cases, restoring a proper calibration and performing a relearn improves shift quality without internal repairs.

Clutch Wear From High Power

Slipping, RPM flare or a shift that feels soft under full throttle usually point to clutch wear. Cars with significant power upgrades are more likely to experience this.

Torque Converter Issues

Converter shudder, slipping lockup or converter damage from heavy use can affect drivability and send debris into the transmission.

Overheating

Track use or extended hard driving can trigger high-temperature warnings. Repeated overheating breaks down fluid and shortens transmission life.

Electrical Faults

Solenoid, sensor, wiring or module problems can trigger limp mode or warning messages.

Our Approach to Performance Transmissions

We start every 10L90 job with a conversation about how the car is driven and whether it has been modified. Tuning details matter, because changes to engine output and transmission calibration affect how the transmission behaves and wears. Then we:

• Road test the vehicle, safely and within legal limits, to verify the complaint.
• Scan for codes and review live data such as slip, pressure commands and fluid temperature.
• Check fluid level and condition with the correct procedure.
• Look for leaks, damaged wiring and cooling system issues.

If the problem is calibration or electrical, we’ll explain your options. If clutches or hard parts are damaged, we’ll recommend a rebuild and walk you through what we found.

Inside Our 10L90 Rebuild

1. Removal and complete teardown of the transmission.
2. Cleaning and inspection of planetary gear sets, clutch drums, shafts and case.
3. New clutches, steels, seals, gaskets and filter.
4. Replacement of damaged bushings, bearings and hard parts.
5. Valve body and control component inspection, with programming as needed.
6. Torque converter evaluation and replacement or upgrade.
7. Cooler flushing, correct fluid fill, relearn and road test.

For modified cars, we can discuss transmission upgrades and performance transmission builds that better match your power level, plus improved cooling with an auxiliary cooler.

10L90 Rebuild Cost

The cost of a 10L90 transmission rebuild depends on the vehicle, the internal damage, torque converter condition, control module needs and any performance upgrades. Because this unit is used in specialized vehicles, some parts may be more expensive or take longer to source than common truck parts. Call us for a free quote. Also check whether your car is still under factory warranty before paying for repairs.

Qualifying rebuilds include our 3-year / 40,000-mile warranty with no deductible on covered repairs. Note that some modifications can affect warranty coverage, so read what voids a transmission warranty. Financing is available.

10L90 Transmission FAQ

Can the 10L90 handle more power?

It has some margin, but added power increases clutch and converter wear. Upgrades and proper calibration help it hold up.

Why does my transmission overheat on hot days?

Hard driving in Arizona heat can push fluid temperature very high. Check cooling, fluid condition and driving style, and consider added cooling.

Do you work on modified cars?

Yes. Let us know about any tuning or upgrades so we can diagnose accurately.