Been working on the autos now about 3 years..Have had the built ones from SZ and others that didn't last that long and then decided to go into it with a few auto techs friends. TT transmission now can suppor over 1000hp with some decent mods, while the stock RE4R03A can support over 600hp with only a few mods. But, to answer your question.. The "Band" and "Servo" if everything else is working (electronics) will give you exactly what your problem is.. One other thing is the "cleat" this metal part fits between the servo piston pin and the band. Based on what you've described I would look at the parts mentioned above to solve your problem. The material comes from the frictions spinning but not enough pressure put on them to engage, go into gear. This material will now cause even more problems while circulating thru your transmission.