Wow--140k, this would be a great time to install some completely new fluid and a new filter. If you haven't done this I'd try that before anything else. Ask around--you sould be able to find a local mechanic/tranny shop that will do this for $50-150.00
The reason why I'd recommend a tranny shop you trust is they can look for damage or failure while doing the change out. Unless you are a tranny guy--you may miss some signs of wear.
I wouldn't cheap out--find the best local tranny guy and take it from there. With luck, it's just some retuin spiff-up needs.