Lexus Repair: automatic trans, leak stop, jp importz

Question
have intermittent chatter shifting into all gears, usually after driving a few miles, not every day.  Have cleaned the pan and filter and used Lucas a couple of years ago until the problem reoccurred a couple of months ago at which time I used Seafoam because the Lucas had a leak stop which I thought was a bad idea which might damage the seals.  Problem is back and I wonder if the viscosity of STP which is similar to Lucas would indicate it might be a substitute?  Also how do you get the rest of the fluid out of the trans--the pan only has two quarts-would it hurt to run the engine with a cooler line off to pump the rest or is a special pump needed?  Thanks

Answer
Hello Clem,
 What kind of vehicle? I'm assuming it's an older ES300. When you removed the pan, Did you see any shaving? Also, Did you clean up the 3 magnets on the bottom of the pan? Did you happen to check the line pressure?  Mostlikely the clutches are burnt. To flush the entire ATF out of the system, You would need a special machine. Most of the quicklube place would have them.  I would do a full flush and see how they will come out. Sorry we never STP or any special additives.  Don't believe on the hype. The leak stop will do more damage than good to your transmission.
JP Importz