2017 with 140k miles not shifting into overdrive gears!!

silkiechicken said:

So update on the situation. No, not stranded yet. lol

Commuted all week without issue on the OEM battery, which is a trip of roughly 43 miles each engine cycle, about an hour of on time, mostly in 6th gear with minimal traffic. Despite scanguage reading battery at 11.9 when sleeping, which is lower than read at the battery terminals, it starts up no problem in 30-40F weather and the alternator keeps it charged up on and off as expected during the drives.

Then yesterday, after about 2 hours and ~40 miles of traffic, traveling between periods of stop and go, slow roll, to free flowing, and back to stop and go... the issue popped up again. I mean, I get it, I too despise traffic. I was trying to pay attention and what I noticed was that there was a solid clunk of what I assume was the transmission, when I was rolling somewhere between 20-30mph. I was not sure if I was accelerating or decelerating, as it was slow rolling traffic, but immediately after the clunk I looked at the scanguage and it was in 3rd gear. I could have been accelerating and it had problems downshifting, or I could have been slowing down enough that it wanted to downshift. I really can't say for sure, as I was just feathering the throttle to scoot along in the congestion. Anyway, immediately after this audible and noticeable clunk, when traffic started moving faster, I was no longer able to get into 5th and 6th gears. Almost as if I had the D4 button pressed, of which it was not pressed. So I pulled off at the next exit, shut down the truck, counted to 20, restarted, and off I went... for another 23, 123, and 76 miles, with minimal slow downs and with no issues.

We will be getting a new battery this weekend and I'll keep everyone updated on how this all goes. I quite like the radiant red color....

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