Flare Shifting?

[ProLean]

Wondering if anyone else has had issues with flare shifting on the non-Aisin 6 speed AT? I've now installed the throttle sensitivity booster which has tightened up the reaction time for initiating a shift but the truck still flares the RPMs and then finally settles in and locks the TC. The truck only has 37k on it and I have only towed my 12K lb. 5er once. I wish it had the quick shifting of my 48RE in my 06 but I have read somewhere that the design of this transmission is a bit different than the 06? I am wondering if I am expecting something unrealistic? It just makes me think the clutch in the TC is hating life.
Has anyone done anything to improve the quality or the speed of the shifting sequence of this transmission? Just curious.
PS...Dealer says its fine. It'll be "fine" right up until it fails at 100,001 miles...just out of warranty.

 

[Missouri Mule]

On the 13's and maybe on up it has to do with the torque converter. Trying keep in good shape and not ruining it.

 

[ProLean]

I know TransGo makes a shift kit for it but I don't know if that will fix the issue and void the warranty.

 

[transe]

Typically, owners who report "shift flare" on the 68RFE are noticing shifts where the TCC unlocks before the shift begins, then the upshift occurs, and then (maybe a second later) the TCC re-engages. The result is that the engine speed increases slightly, then drops (during the upshift), plateaus for a moment, and then drops again (when the TCC re-locks). If you run with a scan tool that displays current gear, target gear, and TCC state, you'll be able to see this. So yes, if this is what you're experiencing, it is indeed normal.

 

[JR]

Mine behaves the same way. It took a little time to get used to but now I don't even notice it. Overall seems to be a tight and under rated transmission. Much better than the previous 46/48RE series. It seems to be the happiest and perform the best with a good load hooked to it

 

[ProLean]

Thanks for the responses. It just seems like my 48RE did the whole "unlock-shift-relock" cycle much quicker. Mine seems very lazy and that's where the the flare hits. I guess I won't worry.

 

[Bowtiepower00]

Mine does- really only noticeable when the truck downshifts while pulling a grade with my toyhauler in tow. Always just assumed it's normal TCC operation under load. I try to modulate throttle to keep it from happening excessively. Transmission temp never gets hot, even pulling 6% grades at 110+ degrees ambient while towing.

 

[spoon059]

Is the truck new to you, or have you made changes recently? How long since you installed the throttle booster? These transmissions learn your driving patterns and make adjustments. The first couple thousand miles that I owned mine (bought used with 10K miles), it had that flare shift you describe. After a couple thousand miles, it smoothed itself out and now I don't notice it at all. I wonder if perhaps the throttle booster could have triggered a new attempt to learn your driving style...

 

[ProLean]

I bought it from my 80 yr old dad with about 33k on it. I think I'm now close to 38k. I've had the TSB on it for only the last 600 miles or so.