Morning. I have a 95 EX sedan with 122k on it. I picked it up recently, but it came old service records. The transmission was last serviced at 90k, and now it stutters when in O.D.
Shifting up and down is fine in all gears, there's no sign of slipping, and the fluid is old (dull brownish color), but the level is fine.

The stuttering is only noticed when cruising at light/partial throttle (usually on the highway), especially when I encounter a mild hill.

I've no previous experience with automatics, but would it be risky to do a simple drain and fill? I realize I'd only be replacing 1/4 of the fluid (if that). Does this sound like a TC, transmission, or ECU related issue?

edit: This happens on 10 min rides, as well as 5+ hour rides, so I don't think it's trans. temp. dependent.

 

could be governor or clutch packs, I would change fluid first as its a 3qt or something like that deal. You can pressure test it, there are a few test ports to see different pressures while in gear. You would have to pick up a manual to do that tho ..