Jeff's 727 rebuild thread

So clearly that pressed steel servo retainer is an issue.... however many modified transmissions do not have this problem, which makes me wonder what the root cause is.

I can see a few possibilities, as below.

Increased line pressure as part of the shift kit instructions which slams the servo down harder.

A mis adjusted or wired back throttle pressure linkage so that the line pressure is significantly higher than it should be when shifting from N to R.

But what makes the most sense to me is a broken or mis adjusted band (too loose) which allows the piston to travel too far forcing the spring and retainer out.

Just trying to figure this out so that we can all prevent it. Clearly the billet piston and retainer prevents it, but what is the cause?