My "93 240, automatic when cold, just leaving the driveway, shifts well through all gears. Very quickly, however, it does not want to shift from 2nd to 3rd gear. the longer you drive it the worse it gets. the only way to get it to shift is to get the rpms up quite high and then abruptly let off of the gas. I replaced the fluid and filter with no result. thinking that maybe there was some varnish buildup on a valve body I put in some Seafoam product in and have driven it on a few short trips(about 5 miles)and it seemed to be getting a tiny bit better. However, I drove it a little farther yesterday and it seemed as though it was as bad as before. Does anyone have any input here? Is there anyting else I can try without a tranny rebuild? Thanks.