Transmission repairs

When's the last time you changed/flushed the transmission fluid?

The experience I had with transmission chains was not good.

Step one is to change the fluid, drive a while, then change it again.

Be sure to change the filter.

Actually there is no transmission "filter." Toyota calls this part a "strainer." The difference would be that filter media, like an air filter or an oil filter collects fine particles which eventually will restrict flow whereas a strainer only sifts out larger particles and would not become restricted. With an air filter you have airborne grit, with an engine oil filter you have wear particles and carbon, but if the transmission fluid is changed regularly, and the magnets in the pan are collecting and trapping any wear particles - BTW magnets trap finer particles than most filters, -- there's nothing left to filter in the transmission - only the strainer as insurance against larger particles contaminating the valve body prior to being trapped by the magnets. There is no filter.

Try changing out the strainer (use a new one, don't just try to clean the old one). Fram has a nice kit with cork/rubber gasket. Clean off the metal sludge from the pan. Refill ATF fluid to the proper level. And see how that works before doing any major work.