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Really poor shifts at light throttle in cold weather
I could use some advice on how to potentially tune out some strange transmission behaviors. It seems like there's a possibility of the offgoing clutches letting go before the oncoming clutches are ready. a shift gets commanded then the engine revs up as if it's in neutral then it grabs the next gear. This seems to only happen during low torque request and outside temperatures around or below 32F. If you request more torque from the 'go pedal' shifts are normal.
I've attached a datalog that shows the pressures doing something that appears funky to me. It looks like it drops the offgoing clutch pressure then builds some pressure on the oncoming clutch but maybe not enough to fully engage the oncoming gear then the pressure drops and slowly builds back up I think this is when I'm noticing the feeling of a neutral gear for a second or so. It looks like it took about 1.5 seconds to build up what appears to be a holding pressure of 506KPa.
*Another transmission question: should it be possible to attain 0 Torque Converter slip when it's locked and under acceleration?
This is in a 2011 F350 6.7 Diesel. dual fuel pumps, larger turbo and a built transmission.