What do you mean flushed properly. Drain and Fill is the way the dealer did it? I agree with the small shops Most will tell you that a syn fluid i Ok it is not JWS3309,MOBIL 3309 andToyota T-iv.They want you to use Syn fluid because its cheep and 3309 is not.

 

Just finished flushing my tranny w/ Toyota T IV atf.
Got them for $5.99 each +tax. The Mobil 1 Synthetic atf is $7.99 @ +tax

 

Using a flush machine drain and fills don't really work . If they do it will return its a waist of money since fluid is not cheap. I've done couple of volvo trans and the flush and reload usully fixes the problem.now depends on how the test drive goes if u having shift flares then engages means have a dirty solenoid sticking most of the time .

 

Drain and fills can be used as preventive maintnance but ur havig problems.