I'll try and make it short.
Did they mention anything about your cvi numbers? (clutch volume index) this can tell you the condition of the internals. This measurement basicly measures the volume /space of the fluid between the clutch's,this can indicate worn components. You need a scan tool, read the cvi values,if they are not in spec, you actuate a quick learn,(with a scan tool only) takes a couple minutes, but it basicly resets the transmission and lets the Pcm,tcm and trans learn together again. He might have not charged you anything because they could tell it was worn out inside and you will be back for a rebuild? disconnecting the battery resets the values and takes time to relearn, but if the reading are not at there predetermined value, or off the charts.No telling when or if it all matchs up again. hope all works out for you, Sometimes this is just a band aid fix.
Yes this is right. The adaptive memory of the trans controller will relearn how fast it needs to fill the piston area's to apply the clutch packs. It has pressure switches that tell the controller when the clutch pack piston has stopped moving and has applied the clutch by building up pressure in the clutch area and if it takes to long from worn clutches or seals it will cycle the solenoids faster that apply the fluid and apply the clutch faster or slower and it also learns your driving habbits. It does this to try and make the shifts fast and light so you can hardly feel the shifts. The pump problem is when you first put the trans in gear in the morning you are telling the controller to apply the underdrive clutch and if the pump presure is not up to par at that time when you first put it in gear the controller thinks it needs to apply the underdrive clutch faster and it ramps the CVI (clutch volume index) count up by cycling the solenoid faster to apply the underdrive clutch faster. Well the underdrive clutch is on in 1st , second and third but not fourth. So when the trans downshifts from fourth to third it will apply the underdrive fast and that causes it to hit hard because the underdrive CVI count may be high since it dont apply fast enough in the morning if it has a pump problem.
Now when they reset the CVI counts which is what the "Quicklearn" does it tells the trans controller to go back and apply the clutches for a normal new trans and it sets the CVI counts back to normal. So now it apply's the underdrive clutch slower but if it knows by not seeing the pressure switch tell the controller the piston takes to long to move and build pressure then it will slowly start applying the underdrive clutch faster and will in time start applying it to fast and then you will have the same harsh 4-3 downshift. It may take a few days or a few weeks if there is a problem there but the Quicklearm can just be a bandaid until the controller relearns if the clutches need to apply faster. Unhooking your battery should not have caused the harsh 4-3 downshift as that most likely was just building up to that harsh shift over time from either worn clutches and seals or a weak pump. Ron
