94 z28, transmission with 230000 miles has delayed shift into last gear but still shifts if i let up on it or punch it a little. replaced 1-2 and 2-3 solenoids; no change. replaced pressure switch; no change. replaced throttle position sensor and vehicle speed sensor; no change. any ideas? i also checked the pressure solenoid and its ok. i think if any components fail in there i will get a code but so far no codes.
transmission runs ok when cold. problem appears usually after it is warmed up and hot.
there are no metal filings in fluid so hardware is ok i think.
help!