[fredjacksonsan]

If the new fluid helped before it may help again. A friend of mine was having tranny problems, he changed the fluid every time the problems returned. After 4 changes his trans was fine for the next 150K miles. Seems like the new fluid had to work its way through, then got diluted by the old fluid remaining inside. Once he'd done the 4 changes all the old fluid was out.

It's worth a try, and hella cheaper than a rebuild.