how do I diagnose trans slipping

[johnmaster]

How do I tell what is slipping and if I can fix it with the tune? Thinking I am going to have to get a shift kit or dish out for a better trans.

99 silverado 5.3 4l60e 2wd 224000 miles, turbo running about 6 lbs right now. Part throttle shifts are crisp but I cant imagine them ever getting firm enough to chirp the tires, they just feel appropriate now that the desired shift is at .2 seconds and pressures are increased a bit (I just copied the performance pressure column to the normal column). full throttle shifts take a long time, about 1.2 seconds from rpm peak to valley, pressure is pegged at 90 during the shift and trq figure is appropriate. Latest drives I took were at 0 seconds desired shift time and still took over 1 second to actually shift.

How do I know it is trying to do everything it can properly but still slipping the clutches? Any cheap bandaids I can do to this thing before I finish it off

[joecar]

Hi John,

The drawn out actual shift times indicate friction material slipping during the high torque shifts...

unfortunately there's no fix short of a rebuild, there are no band-aids, the friction material is worn thin/thru;

anything over 200K miles is a bonus;

[johnmaster]

Hi John,

The drawn out actual shift times indicate friction material slipping during the high torque shifts...

unfortunately there's no fix short of a rebuild, there are no band-aids, the friction material is worn thin/thru;

anything over 200K miles is a bonus;

Thank you Joe, thats kind of what I figured but wishful thinking had me second guessing. Will have to start looking at my options now. If I wanted to stick with 4l60e is there a consensus on properly modulating pressure for a boosted application? maybe I should segment swap and put a 4l80e in...this trucks life isn't going to get any easier.