Transmission hard shift and high RPM

New to this section. My sons 2000 Tacoma 2.7L automatic has 150K miles and it has a continuing tranny condition. It shifts fine through the gears fine, but shifting into R or D it shifts hards. It seems it do it cold or hot. The engine seems to be idling higher then normal, could that possibly causing the hard shift ? Don't have an tach to check anymore. Also stopping at a light it seems to downshift into 1st gear after you set for sometimes 25 seconds later, and sometimes it shifts into 1st just as let off the brake and accelerate, klunk shift and it goes. Kinda make you cringe. Just had it at the tranny shop, of course they can't find anything wrong, no codes. They changed the fluid and filter. It still shifts into the gear hard. Any ideas will help.

 

A good place to start is the high idle .
Look here for some info http://www.tacomaworld.com/forum/te...warner-340-series-transmissions-write-up.html