The 4R70W was introduced in 1993 as an evolution of the AODE, but with a wider gear ratio for better performance and fuel economy. This unit, as with any modern unit, is susceptible to valve and valve bore wear and those are replaced with improved aftermarket components. Some common failures specific to this unit are:
Worn pressure regulator valve causes pressure control issues. New hardcoat anodized pressure regulator valve is installed.
Intermediate one-way clutch retaining ring opens up and pops out of its groove under higher RPM. A spiral locking ring stops this failure
Many other components replaced in these units that are normal to any later automatic transmission; the list above is 4R70-75W specific. Our experience at PowerSource is unmatched, so feel free to contact us via the Chat option or call us on the toll-free line and we'll be happy to do more than read a script to you; we have actual building and repair experience.