Common in Chevy/GMC 2500/3500 HD trucks, Express/Savana vans, and other GM platforms using RPO MYD. We’ll confirm fitment by VIN/RPO.
Yes. Perform a full reprogramming appropriate to your year/build and complete an adaptive learn/relearn drive cycle to protect fresh clutches.
Yes—each build includes a matched lockup converter configured for towing, daily, or performance use.
Flush/replace the cooler & lines, verify strong return flow, and consider an auxiliary cooler for towing/hot climates.
6L80 (RPO MYC) and 6L90 (RPO MYD) are different internally. Always verify RPO before ordering.
*HP figures are guidance; vehicle weight, tires, gearing, load, and tuning affect capacity.
Jump to: Capacity & clutch strategy • Converter/TCC heat control • Cooling & return flow • Install checklist • Programming & adaptive learn
The 6L90E is the heavier-duty sibling in GM’s 6-speed family (RPO MYD). Under towing and heavy vehicle weight, clutch apply timing and heat management are everything. Our tiers increase clutch capacity, stabilize hydraulics, and match the package to your duty cycle so it holds without flare.
High load + PWM lockup is where temps climb. We include a matched lockup converter strategy to reduce slip and stabilize lockup. If you tow, the cooler/return-flow setup matters just as much as the transmission build.
Use fresh DEXRON-VI, flush/replace the cooler and lines, and confirm strong cooler return flow. A low-restriction auxiliary cooler helps protect clutch packs and the converter under long grades and hot weather.
Perform a full reprogramming (TCM/TEHCM) appropriate to your year/build, then run a light-throttle adaptive drive cycle— progressive upshifts and gentle coastdowns—to seat adaptives and protect fresh clutches.
6L80 (RPO MYC) and 6L90 (RPO MYD) are different internally. Verify your RPO before ordering to ensure fitment and durability.
Yes. A full reprogramming is required after install. Then complete an adaptive learn drive cycle.
Yes—each package includes a matched lockup converter (higher-capacity strategy on Sport).
DEXRON-VI. Capacity varies with pan/converter; verify level at temp using the correct procedure.
Cooler/return-flow verification, fresh ATF, deep pan (capacity/heat), and year-correct TEHCM + proper programming.
Drop temps and protect clutch packs under load.
CoolingExtra capacity + better heat rejection for towing.
CapacityStart fresh after install and set level properly at temp.
FluidYear-correct electronics; reprogramming required after install.
Electronics