As Merlin states the rear planetary up until final production of this series of transmission continued to be an Achilles heel.
Even the 5 pinion planet sets were just as susceptible to failure as the early 4 pinion sets were. The harder the owner drove the vehicle, the more likely the planet set was to fail. Any type of racing, towing, or other intentional abuse would drastically shorten the planet sets life. The secret to a long living 700/4L60E is to use it in exactly the manner that GM intended-as a basic daily driver, non-work, non-racing, non-hi-performance, non-towing, vehicle. When used CORRECTLY in that manner, you are guaranteed to go at least 150K miles. If you attempt to do anything else OTHER THAN using them as daily drivers then it's a roll of the dice and snake eyes usually equated to a stripped sunshell or failed low planet set, or broken input sprag, or burnt 3rd & 4th clutch pack, or stripped turbine shaft to input drum, or.... you see where this is going.