4th Gen 8speed Shifting Question

[Woodgrain]

So my ram is a 2015 quad cab sport with 50k miles. I have noticed a few things about the 8 speed trans:

- the below has been happening roughly the last 7500 miles (or as far as I can remember) but has not gotten worse
- slight flare of 200 - maybe 300 rpm only on the 3/4 upshift, all other shifts are butter smooth up/down
- happens only below ~ 2000 rpm whether warm or cold
- never towed with the truck, just casual daily driving and taking the occasional mattress to the dump (no off-roading, I have a ram-charger on 37's for that)
- light throttle seems to be the usual way I can make the flare? re-occur
- under minimal rpm, it rarely happens
- does not feel like a slip, truck keeps accelerating under power, when I test my theory and get the truck to shift at 3k+ rpm, it is fine and smooth on the 3/4 upshift

Tried to find a similar case and cant quite find anything else fitting the mold of my description.
I did read about someone having a rare flare on a 2/3 upshift and someone mentioned air purging? But hard to compare

Oh, no bangs or clunks or engine lights, trans temp stays normal operating temp and has never overheated. Tried a re-learn, but still persists.

Any thoughts greatly appreciated, thank you!

 

[Mister Luck]

The 8HP transmission can shift gears in as little as 300ms

Do you have 4WD or 2WD and if you have 4WD does the transmission act the same in 4WD as 2WD

Which rear gear ratio differential? do you have limited slip ?

In my personal use having 4WD crew cab 5.7 with limited slip rear diff. that it is all in pedal feel and how aggressive or passive that response is.

I have an accelerator pedal accentuater if and when I don’t use it I notice random learning curve for shifting.

But in 4WD HI I experience it less and in 4WD LO it doesn’t exist.
including after returning to 2WD

The ZF8HP is self adjusting and wear is compensated for to where it is basically unnoticed.

 

[Woodgrain]

Truck is a 4x4 quad cab 6’4 box with 3.92 gears. We had a bit of snow so I was driving in 4hi a little bi here and there. I put on another 150 miles yesterday, driving like a grandma, very pedal conservative. Flare was happening maybe 60% of the time, and the rom burp was only 150ish rpm on the 3/4 upshift. When I merge on the freeway, all shifts over 2k have been and still are butter smooth. 0 hard shifting, downshifts are normal, still perplexed, but the learning of the trans seems the most fitting. Who know? Ive only noticed the last 7500 mils or so because I have been doing a little more city driving than previous years. Going to keep driving it super easy for a week and see what it does. I appreciate everyones input.

 

[Jwrigh12]

This! I would love any other info you have. My truck seems to be doing something very similar. Its the 3-4 up shift under light pedal conditions. The only other thing that I've noticed is a pretty pronounced "kick" when doing an aggressive pass. If I'm in 8th and I hammer down, it will drop to 4th and you can for sure feel it. I suspect thats relatively normal, but thought Id bring it up in case its an indicator of something else.

Again, same as Woodgrain, no slippage... just feels... sloppy? Compared to the rest of the shifting. I have a 2014 with admitidly many more miles (148k) 4x4 Crew Cab. Build Sheet states 3.21 gears, but the truck had 35" tires when I bought it used about a month and a half ago. Only noticed the 3-4 shift thing for the last few hundred miles, but Im still learning the truck.

 

[Woodgrain]

Ive realized if I am not focusing on it or looking for the 3/4 shift, I am not really noticing it at all anymore. Might be the way I have been driving the last 1k miles? Never had a hard clunk or anything out of the ordinary. Flare of 100-200 rpm seems to happen on random occasions.