The transmission is hesitating to go into overdrive and at times not even going on 1995 Chevrolet G Series Van (G30)

Just started.Transmission fluid and filter were changed about 2000 miles ago.But not flushed,only drained.

Asked by for the 1995 Chevrolet G Series Van (G30)
filter as well?? dod you change it regularly??

it sounds like the clutches may be failing.

Does it do it when cold or hot? Also the best oil to use is full synthetic trans oil which means you must flush it cause you can't mix oils, synthetic oil withstands much higher temps
but it sure as hell sounds like the clutches, does it take long to go in to reverse after being in drive? That's also an indicator of worn clutches