Hmmm, never heard of this with a 727. On GM th400's/th350's, the sprag that holds second gear supposedly gets shocked by the tires spinning, then shocked again by the shift to second when doing burnouts in a burnout box say. This causes the sprag to give and you lose second gear. The key is to start in second or start to spin slowly in/through first instead of just pounding it to avoid shocking the drivetrain. That's the belief, although I never had a problem with it in my th400 and neither has my boss when I asked him who has been professionally building race cars (his own car being an 8 second camaro) for 30 years. With the gm tranny anyway, personally i think it only becomes a problem when you are running slicks, doing a burnout in the water box and shift into second very quickly after romping through first. You're heating the tires up a lot by spinning hard in first, then you hit second and they'll hook/shock the sprag. I try to ease into my burnouts to avoid such shock. The best idea would be to slowly go through first, then after you get into second you can get into it. I don't think the drivetrain shock is as much when just spinning without powerbreaking as you probably wont get through the gear as quick due to more load.
...thats if the problem is the same for the 727a....i'd like to learn more
