Owner was having trouble with 2,3 shift flares. After test driving the truck the truck would intermediately slips between 2nd to 3rd. Which was a sign that the 3rd & 4th clutch pack was about go.

Symptom;

2nd to 3rd flare, rpm will rev before the transmission would shift to 3rd.

Issue;

3rd & 4th gear frictions were worn, 3,4 pistion was worn.

Solution;

add master rebuild kit, new torque converter