After the trans fluid (Castrol high mileage) and filter were replaced, the transmission slips especailly when the gas pedal was depressed after slow down. I checked the oil level a coule of times and it checked out fine. When I replaced the oil/fluid, a bottle of Lucas Transmission Fix was added for just in case. It seems that the transmission does not like new oil. With old fluid, there was no slip. If I kept the old oil, I will try to put it back but it was trashed ( i mean properly). Does anyone have any idea about how to?

Did you check the trany fluid level when it was hot ?

If it was and its slippin, it's probly time for the trany shop!!
Could be many things though.....

The level was checked after I following the procedure on the manual, and so it was warm/hot. It seems that the new fluid is too thin to convert torque. Is there any quick fix like adding more thick fluid? If the TM needs service I would buy a new car since it may be more than the car value.

If you put in trans fluid then its the viscosity that it's supposed to be.... thiers not anything you can do for that.

Could be something simple such as a shift solenoid but it could also be something more drastic. The only way to "know" is to have it properly diagnosed by a trans Tech.

Good Luck

It seems that the Torque Converter Control Solenoid is the culprit. I am collecting info and direction for replacing TCC solenoid. To do this, it seems that I need a engine jig and a crane. If there is anybody ever replaced TCC solenoid, please give me some detailed directions.

One option I am thinking is to remove thermostat to decrease T-mission fliud temperature, eventually to increase viscosity. Has anybody tried this trick?

Yeah, I've replaced 1-200 of these before it sucks!

Heres a link for the procedures...
http://autorepair.about.com/cs/doityourself/l/aa011703b.htm

Good Luck