3 WORST and 4 BEST GMC Transmissions EVER Made

Some GMC transmissions last 300,000 miles. Others blow up at 80,000. In this video, I break down the 3 worst GMC transmissions you should avoid at all costs — and the 4 best ones that'll outlast your engine. 🔧 In this video: Transmissions that fail early The ones mechanics trust What to look for when buying used 👇 WATCH NEXT: • 3 WORST and 4 BEST GMC Engines You Can Buy • GMC Trucks That Will Be WORTHLESS in 2026 🔔 Subscribe for weekly GMC tips! #GMC #GMCSierra #GMCYukon #GMCTransmission #Allison #6L80 #6L90 #10Speed #GMCTrucks #TruckLife #GMCDenali #Duramax #TransmissionProblems #GMCNation #TruckTips