Strange Shift Hesitation

Hey,

I searched around & couldn't find a thread on exactly what I'm experiencing. I just want to know if it is "normal" for this truck or if I need to look into it... I just picked up the truck last week, 2015 CM Limited with 122k.

When I'm in third gear and going from ~25-60mph, the truck has about three places (around 2500, 3500, 4500 RPM roughly) where it seems to initiate a shift & then say "nevermind". It's never rough, and the shift when executed is never rough either. I don't know if the torque converter locks on acceleration like this, but it almost feels like it unlocks for about a half second at a time & the truck stops & then continues accelerating.

If I'm light on the pedal, it will upshift early as expected, and if I'm WFO it will go smoothly to the redline before shifting as expected. The phantom shifts only seem to occur under medium/"normal" acceleration.

Is the truck "getting used to me"? I have pulled the battery cables & also cleaned the MAF and throttle body. Service history other than a dealership oil change is unknown.

Thanks for any insight... sorry to be the new guy that posts an extremely nitpicky question like this.

 

I would have a drain and fill done, just in case the previous owner never did it. The only real issue I’ve noticed with my transmission is once in a while when the truck downshifts to go up a hill it will hang in the lower gear way too long after reaching the top and going down. I plan to mention this next time I take it in for service. What you’re describing doesn’t seem normal to me.

 

Is it a little bit of a "bump" when you hit the gas again? These trucks have flex-lockup torque converters and use a linear solenoid to be able to move between locked and unlocked, and transitional states in between.

 

@tttrdpro Thanks, I will check into this.

@Oats87 I am not letting off the gas, this occurs when I'm holding the pedal completely constant. It just feels like a blip of power loss, either like the fuel or the engine/transmission link is momentarily disrupted. In any event, it never feels jerky or bumpy, its a smooth-but-quick interruption. Feels a little bit like gently slipping a manual transmission, but only ever happens in 3rd...

 

I would do a drain and fill of the trans for sure. Also, the trucks "learn" the driving habits- shift points, MPG, etc....erase that from the previous owner's use and start fresh- just disconnect the battery for 30 minutes to clear everything and it will "relearn" from your driving habits