ATF: To Change or Not to Change

Hello forum,

So I have a 1988 Eldorado Biarritz with 180xxx miles.
The car has been meticulously maintained since day one and has had no major problems, but I have a question.

Under normal driving, the transmission seems to shift "funny." Shifts, especially 1-2 and 2-3 gears, are a little rough and slow, especially under slow to moderate acceleration. Punch the gas, however, and the car shifts quickly. I have never noticed it slip, and all the gears seem to engage.

As far as I can tell, the ATF has not been changed in years, and definitely not in the last 30,000 miles. I'm wondering if it might be time, as I don't know if it's been changed since 100,000 miles anyway.

Could anyone tell me what, exactly, to look for on the dipstick and whether or not a change is necessary? What about a flush?

Thanks!

Is the fluid clear and red? Tough question without an accurate history usually doing that will not cure a problem if the filter is restricted there are worn clutches. Only pulling the pan will give some idea.