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Showing results for tags '8speed'.
Hi everyone, I just purchased a 2016 GMC Sierra SLT Crew Cab All Terrain X a few weekends ago. The AFM (Active Fuel Management) is such a pain when switching from V4 to V8 mode at low speeds (non-highway driving) because I hate the "bogging" or "hesitating" feeling the truck gives off and the exhaust tone is UGH... I had a 2007 Avalanche and used a Range Technology device to disable it. But overtime I would have to pull the device out and plug it back in because it wouldn't activate sometimes. Been reading on this forum about the Range device for the newer Sierra's and people have been having issues with them and could mess with the computer overtime. So I won't be going that route. Another option is to get a tune like BlackBear and get it disabled or set a minimum speed of when the AFM activates. But a tune isn't an option for me right now because I want to keep my warranty as long as I can. Someday BlackBear tune will in my future! So I decided to try something. For the last couple days I have been driving in Manual mode "M" and setting it to M7 (7th gear) and driving like normal (non-highway driving). I was shifting gears up ( + ) and down ( - ) because I thought that was what you were suppose to do but I found out I can just set it to M7 and not worry about shifting, it does it for me, it just doesn't go into M8 (8th gear), which I don't need when I am going less then 50mph most days. I watched it stay in V8 mode stay the WHOLE TIME! The only time it went into V4 mode was when I shifted into M8 and then I switched back to M7 and it went back into V8 mode. So I think I found a workaround without having to void my warranty with a tune or messing up my computer with a AFM disabler device. I want to get your thoughts guys, will running in Manual "M" mode ruin the transmission in anyway? Not using M8 (8th gear) for slow speeds have long term affects with that gear? I am going to do this for another week or two and report my findings. This guy is happy when my truck isn't "bogging" or "hesitating" and have full power!!!
I recently bought a new 2018 Silverado 1500 Crew Cab LTZ with the 6.2 liter & 8 speed transmission. I bought the truck in Idaho (great deal) and drove it home to California. Since then I've only put a few hundred more miles on it, 1181 total miles to be precise. Yesterday the tranny started shifting really hard & clunking on downshifts. Today, when I put the truck into drive it barely moves! Obviously, the transmission is slipping as the engine revs but the truck doesn't really move much! Any info on if the truck can still be returned at this point or am I stuck rebuilding a brand new tranny? Doesn't seem right to have to go through this so soon! I hope GM will either let me return the truck completely or give me a brand new transmission. Any insight on what may happen would be appreciated! Thanks in advance!