2009–2014 GMC Yukon 6L80 Transmission Repair
The 2009–2014 Yukon with a gas V8 uses the 6L80 (hybrid models excluded — they use a different two-mode transmission).
Transmission at a glance
Year-specific notes
- 2009 — 2009 is the first model year the 6L80 was broadly used in this SUV.
How to confirm your transmission
- Check the RPO code sticker in the glove box: MYC = 6L80, MYD = 6L90.
- The 6L80 case has an integral bell housing and a flat, bolted aluminum pan with a drain plug.
- A VIN lookup or scan-tool module ID confirms the unit before parts are ordered.
Common 6L80 failure areas in the Yukon
Often tied to worn valve-body bores, a leaking lower-body seal, or TCM adaptation issues on this generation.
A frequent 6L80 complaint on these trucks; converter clutch wear and fluid condition are the first checks.
Commonly the 3-5-R clutch pack or its piston seal; a burnt 3-5-R pack is one of the best-known 6L80 failure areas.
Pump bushing or pump wear, sometimes following fluid overheating in towing or Arizona summer traffic.
Diagnostic considerations
- Scan for stored and history codes in the TCM, then review clutch slip and pressure-control data live.
- Check fluid level through the check plug at correct temperature — the 6L80 has no dipstick.
- Road test for converter slip and shift quality under load, then check TCM software level.
Repair or rebuild?
Some problems — software, solenoids, a valve body or a converter — can be repaired without removing and fully rebuilding the unit. When clutch packs are burnt or there is metal in the pan, a rebuild (or a replacement unit) is usually the dependable fix. We show you what we found before recommending either.
Other Yukon generations with the 6L80
Closely related vehicles
Request a quote for your GMC Yukon
Frequently asked questions
Should I rebuild or replace the 6L80 in my Yukon?
It depends on what failed, the mileage and the condition of the case, valve body and converter. We diagnose first, then explain the options before any work begins.
Do you give prices over the phone?
We don't quote a price before diagnosis because repair scope varies widely. Call 602-725-6800 or request a quote and we'll explain the next step.
Where are you located?
MBN Auto Diesel is at 6602 W Myrtle Ave, Glendale, AZ 85301, serving the Phoenix metro.