GM 6L80 6-Speed Automatic · GM/Chevrolet/GMC/Cadillac/Buick · Expert rebuild service since 1987. Lifetime warranty. Free diagnostic.
2006–2018 Chevrolet Silverado (5.3L/6.2L), Tahoe, Suburban, Avalanche; 2006–2018 GMC Sierra/Yukon; 2006–2011 Cadillac Escalade, STS (V8); 2010–2015 Camaro SS; behind all LS/L83/L86 V8 engines
| Configuration | 6-speed automatic — main GM full-size truck/SUV transmission |
|---|---|
| Gear Ratios | 1st 4.03:1 · 2nd 2.36:1 · 3rd 1.53:1 · 4th 1.15:1 · 5th 0.85:1 · 6th 0.67:1 · Rev 3.30:1 |
| Fluid Type | Dexron VI ATF |
| Fluid Capacity | 11.4 qts total, 5.5 qts service refill |
The most common 6L80 complaint — TCC shudder at 40–60 mph under light throttle is a nearly universal experience at 80k–120k miles. Primarily fluid-related on early complaints; converter replacement on persistent cases.
Symptoms: Shudder or vibration at 40–60 mph; feels like rumble strips; worse under light throttle; clears under hard acceleration
The 6L80 uses 5 variable force solenoids in the valve body. Solenoid wear causes pressure control faults and erratic shift quality. Common at 100k–150k miles.
Symptoms: Erratic upshifts; harsh shifts; P0961–P0972 codes; limp mode
High-mileage 6L80 front pumps wear at the vane tips and pressure plate, causing low line pressure. Often manifests as TCC shudder that doesn't resolve with fluid service.
Symptoms: Low pressure confirmed on gauge; TCC shudder persists after fluid change; multiple gear slip
Full disassembly. TCC inspected and replaced. VFS solenoids replaced. Pump vanes and wear ring inspected. All clutch packs replaced. Valve body cleaned, new separator plate. Full Transtec soft parts kit. Converter replaced if TCC worn.
Dexron VI every 40,000–45,000 miles. TCC shudder resolved with fresh Dexron VI in ~60% of cases — always try a fluid change first. GM issued TSB 14-07-30-004 for 6L80 TCC shudder addressing this issue.
Start with a Dexron VI fluid flush — this resolves the majority of 6L80 TCC shudder cases. If shudder persists after 500 miles on fresh fluid, the torque converter's lockup clutch is worn and needs replacement.
Yes — TSB 14-07-30-004 addresses TCC shudder in 6L80/6L90 units. The fix is a Dexron VI fluid flush with a revised fluid formulation. GM dealers and transmission shops can perform this service.
150,000–200,000 miles with regular Dexron VI service. One of GM's more reliable modern transmissions.
The 6L90 is the heavy-duty variant with higher torque capacity for 3/4-ton and HD applications. The 6L80 is for 1/2-ton trucks. Different torque ratings, mostly shared parts.
$2,000–2,800. 2–3 day turnaround.
Free diagnostic, written estimate, lifetime warranty. Chicago's 6L80 rebuild specialists since 1987.
