Hey all, not an idiot but there are some oddities with my transmission and I want to get some input. 1997 D1 with A/T, of course. Truck sat for over a decade, I've changed the oil, transfer case and diff fluids and maybe put 1500 miles on it. Transmission is...sluggish. It shifts early and tends to "flare" between gears. Otherwise OK. Don't know how out of the ordinary this is if at all.

Some facts:
Fluid is overfilled. See pic. Not a ton, but too much, maybe a couple quarts. Checked with the truck running, tranny cold and in Neutral after shifting through the gears, per the manual (and dipstick). I've always checked transmission fluid with everything warm. When warm, fluid is WAYY up the stick and bubbly bordering on foamy.
Fluid is reddish brown and very light/clear. It doesn't smell burnt. Really it just smells like transmission fluid. Since its overfilled, I know this is not the original fluid but I have no maintenance records whatsoever.

Some questions:
Check transmission cold: really?
Am I inviting leaks at the drain plug by draining a quart and re-tightenting?
Clearish reddish-brown fluid--seems to me this would indicate relatively good condition.

My idea:
I was thinking of simply draining a quart of fluid and testing again. Rinse and repeat until I'm in the range. With the fluid as clear as it is, I don't think I need to muck with the filter right now. I don't relish doing a full pan and filter if I don't need to.
Other idea: drain as much as I can and put less back. Basically replacing ~50%+ of the fluid.

Thoughts?

 

Seems like you’re checking it correctly, engine on but cold. Although I tend to check level at different temps and take an average reading. What do you mean the gears “flare”?
I would drain about a half-quart and check for color and any shiny metal particles.
No idea why it would be foamy. Is it the correct Dexron Mercon fluid? Lots of people here recommend Valvoline Maxlife.

 

drain and refill

check the transmission cable on the throttle is tight enough

 

By "flare" I mean it seems to be taking a little too long between gears. The opposite of jerking quickly into the next gear.

I have no idea which fluid was used. Based on the overfill, I assume it was done at the local Kwik-e-Lube and who knows what they would have used.

 

I'd drain and refill since you don't know what's in there. I use the below from Wal Mart. It's only $14/gal.

I changed mine at 242k and it was brown and smelled burnt. Who knows when it was last changed. No issues since the change and I'm currently at 258k.

Valvoline DEX/MERC Automatic Transmission Fluid (ATF) 1 GA

 

I was curious about using this instead of the red, as this is DEX III and the red is DEX VI which is far from what the manual recommends (DEX II).

I would also recommend some Lucas Stop-Slip which you’ll find in the tech section. My transmission likes to hesitate a bit when taking off from a stop, and the Lucas does wonders for that.

 

Either the blue or red Valvoline will work Dex = Dex as technically Dex II was surpassed by III/IV.

Kickdown needs to be checked. If out of adjustment it'll hardly want to shift down until your foot is thru the floor. Also I've noticed HD/Severe fan clutches put more of a load on the engine and depending at the speed your driving if the fan clutch is engaged the shift could feel delayed/rough due to the load from the fan clutch.