2-3 shift lazy

[06silvercrew]

My new (to me) 06 PSD with the tqshift trans has a very lazy 2-3 shift. 1-2 will snap your neck, the 3-4 & 4-5 is good. I put the SCT X3 on it thinking it might firm it up some, but still sloppy. Is this charactoristic of these? Im a GM tech and am used the the neck jerking shift of the allisons. Is there an update for the PCM that anyone knows about? Ive looked on alldata, no luck, but I do know thats not always up to date with the latest info. I've got an appointment monday to get it checked out, as its got 35,250 miles and want to get it looked at before it goes out of warranty. Just wanting your guys input on how yours shifts. Thanks in advance.

Scott

 

[Boadie]

2nd gear is actually overdrive and first, when you go to shift into third the tranny is having to drop both 1st and od and shift into 3rd, So I have been told. I have always had a clunk with two different transmissions shifting from 2nd to third. I agree the shift point is not as sharp as the rest. Ford has said many of times to me there is nothing they can do about it.

 

[06silvercrew]

Engine torque is transmitted in 1st, 3rd and 5th gears while the range selector lever is in the (D) position. The input shaft drives the overdrive carrier clockwise. The overdrive carrier has the coast clutch hub bolted to it which also turns clockwise. The overdrive sun gear would turn counterclockwise, but is held from turning by the coast clutch mechanical diode. The input shaft turns the same speed as the center shaft and transmits torque through it.

In 2nd, 4th and 6th gears, the overdrive clutch is applied, the mechanical diode overruns and holds the overdrive sun gear fixed to the case. This causes the overdrive planet to walk around the sun gear and over-drive the overdrive ring gear


Im a transmission Tech, I understand completley how and why it works, still doesnt explain to me the lazy-shift.

 

[f100cleveland]

I had the 2nd to 3rd rpm flare too but it got better when I ran with the edge evolution and seems to go away alltogether now that I'm running a SCT X-3.

 

[atk]

mine has the same condition. did get better with the SCT....but i haven`t tried all the tunes yet...i know, doesn`t help much....

 

[Kleetus]

I would suspect either it's a dirt issue, or fluid flow. Think about it, you're now applying two servos, if either or both are out of spec, or close to it for leakdown, the combined loss might account for why it takes longer. Either one by themselves has enough pressure to overcome whatever losses are there. Add them up, and it gets skinny. Could also be a solenoid issue too, ie, reaction time is slightly longer than expected, hence non crisp operation.

So why the 2-3 shift? no idea, could also be flow restrictions in the valve body, based on location of orifices of the solenoids. Meaning if the solenoid isn't symmetrical, if it's put in one way vs another, could result in 180 degree fluid flow versus some number less than that.

Don't know. Just thoughts that run through my head about any hydraulic system.

 

[06silvercrew]

Im leaning towards the fact that its probably nature of the beast. I also think its a calibration condition within the PCM. Was hoping maybe there was an updated clibration or something.