well, i'm still on my original 4 spd trans on my 2007 Avalanche, that i bought new, over 7 1/2 years ago.
75,000 miles pulling a hybrid about the same weight.
Dan- Firefighter, Retired:C, Shawn- Musician/Entrepreneur:W, Zoe- Faithful Golden Retriever(RIP:(), 2014 Ford F150 3.5 EcoboostMax Tow pkg, 2016 PrimeTime TracerAIR 255 w/4pt Equalizer and 5 Mtn. bikes and 2 Road bikes