Thanks for the reply guys.
I drained the pan, removed and cleaned, no plug found in pan. Then drained the converter. I purchased 4 gallons of fluid and used almost 15 quarts to refill. No issues filling converter (I assume there is enough residual fluid to lube the pump and keep it from cavitating). I refilled the trans with 2 gallons of fluid, ran the car for 1 minute, shifted through the gears, then added the 3rd gallon of fluid. Took a 15 minute test drive and added more as needed. I will check for the next couple of days to make sure the level is correct under all temps and loads.
I have read the "Mercon/MerconV/MerconVI" controversy and settled on Castrol's Transmax High Mileage, it is a Mercon compatible fluid. The service was done in my driveway and only took 1-2 hours (this was my first time doing it myself, so I took extra time). This service cost less than $100 for fluid, filter and brake cleaner.
From Castrol's site;
Description
Castrol Transmax™ High Mileage Automatic Transmission Fluid is a premium ATF specially formulated for maximum transmission life in high mileage vehicles. Castrol Transmax™ High Mileage ATF has been engineered to help alleviate typical problems experienced by transmissions with over 75,000 miles such as leaks and rough shifts. Newer vehicles will also benefit from this technologically advanced formulation. Greater frictional durability provides superior transmission performance.
Advantages;
Manufacturer Specification
The most applications amongst high mileage transmission fluids and suitable for use in vehicles as indicated below:
Acura ATF-Z1 (except in CVTs)
Chrysler ATF+3®, ATF+2®, ATF+®
Ford MERCON®
General Motors DEXRON®- III H, II-D, II, DEXRON®; 9986195; Type A, Suffix A (TASA)
Honda ATF-Z1, ATF DW-1 (except in CVTs)
Hyundai SP-II, SP-III
Infiniti Matic-D, Matic-J, Matic-K
Lexus Type T, T-III, T-IV
Nissan Matic-D, Matic-J, Matic-K
Toyota Type T, T-III, T-IV
Volvo All Specifications
Warranty and Protection Requirements
Exceeds all passenger car and light truck manufacturer’s warranty requirements for vehicles, transmissions or power steering service where a DEXRON®-IIIH or MERCON® type ATF is specified
Industry Specifications and OEM Approvals
Meets or Exceeds General Motors DEXRON®-IIIH Requirements
Meets or Exceeds Ford MERCON® Requirements
After the service;
The trans shifts smoother and locks up quicker. When the cruise control is on and climbing , it doesn't downshift automatically as much. I assume it's do to the converter locking up more efficiently.
I am halfway though my first tank full after the service, but it looks like I am getting better mileage. Prior to the service I was getting 15-15.8 mpg on the highway with a 5.4, AWD and 238,000 miles. I will report back after a few more tanks.
Thanks again, Steve.