Ok-- I've had a couple of weeks in it--
my first tank with careful driving yielded 18.0 mpg before any work was done.
dealer did the WP and TB to the tune of $850+tax.
Amsoil SG 75-90 went in the LS diff. The driveline makes less noise-- best way to describe it, and the engine braking doesn't seem quite as pronounced when coasting. Not sure what was in there before, but it wasn't too old-- maybe 15k on it, tops.
Swapped out some nasty fluid for amsoil PS in the steering. 2 bottles out, 2 bottles in. Feels the same, very slight difference, hard to describe.
Read up on the BG universal ATF in the trans. Good for "everything," T-IV, ATF+4, Dex, Merc, etc... Too bad this AT calls for the WS ATF, which looks to be basically a lower viscosity fluid. Amsoil, for example, has a specific ATF for toyota WS and Dex VI. IMO the "universal" would be too thick...
The sump only holds... something like 1.7 qts. Drain/fills would take forever. And I didn't want to spend on a full amsoil flush.
SO GET THIS:
I stuck the mityvac on the cooler line from the trans and pulled the fluid out that way. Got 4 quarts out and stopped (could have gotten more, but I only had 4 quarts). The first 1 3/4 came out easy, then it started bubbling. I ran the engine then for about 20 seconds and the mityvac pulled the remaining out without much trouble-- there were bubbles in the line but it was very effective. filled 4qts in via the return line, patiently.
The amsoil feels better. doesn't bang into gear... its more civilized perhaps. it still shifts just as quickly, but with less of a jerk.
Now I'm almost wishing I had more than 4 quarts on hand when I did it. I don't want too thick of a fluid in there pushing pressures up higher than they are supposed to be.
I think 4 qts is about half of the total capacity... IIRC it doesn't hold very much.
Anyway, new technique--- I figured it'd be effective b/c the TC fills and drains from the center... so pulling a vacuum on it while turned off would let the air bubbles rise to the top of the converter and i'd basically have access to 1/2 the fluid in the thing. It wasn't perfect... air was coming in from elsewhere, but it was certainly more effective than draining the pan.
Plugs need to be checked soon, possibly replaced. Will report back...
M