My auto-trans su*ks... after car is warmed up.. auto trans still jerks..changing gears.. P<->R<->N<->D specially on D mode.

Last month I payed $1000 for trans-rebuilt at local Honda Repair shop.. I still have life time warrenty on it..
If it get little more worse I will go and compain about it..
Mean while...
What is the best auto trans cooler for F22A1 and how much is it?