[DNA Dan]

I'd start by changing the lead frame and putting fresh oil in it. There's not much more you can do to address known transmission issues without pulling it and digging into it. There is a tsb on the lead frame, yours may or may not be covered.

 

[DNA Dan]

Hi Dan, thanks for the idea. After already replacing my transmission once and going through the dealership trying to get them to chance the lead frame and then denying because the symptoms are different, I'm desperate to find the real solution before throwing parts at it.

Unless you're a transmission guy, there's no other parts to really throw at it. If that doesn't fix it, you'd have to do a complete rebuild and it's probably just cheaper to replace with a new one.