Too late to change auto trans fluid?
 

My Z overheated about a year ago and I never changed the trans fluid. (I have an auto) It's grinding/whining now and i'm going to change the trans fluid (amsoil) and the filter. Do you all think it's too late and would it fix the problem?

Probably too late. But might as well change it now and see what happens. Worst case is you're out $20 for transmission fluid. Best case is it fixes your problem.

Disconnect the cooler line from the passenger side port on the radiator and run that line into a 5 gal bucket. I like to run the line into a 24" piece of clear tygon tubing so I can watch the flow. Start the engine and let it idle. The tranny will pump out the old fluid. Stop the engine the moment the fluid stops flowing. Reconnect the cooler line to the radiator and then drop the pan off the tranny to finish draining and clean up the pan. Look for large bits in the bottom of the pan or excessive clutch media (the silver sludge). I wouldn't mess with replacing the filter. Its not a media style filter, but a fine mesh screen. Two of the bolts holding in this filter do not have captured threads in the valve body, but are held by nuts on the top side. Unless you are prepared to drop the whole valve body, I'd leave the filter as is. Find the vacuum modulator on the drivers side of the transmission and pull off the vacuum line. If the line is clean and dry, the modulator is probably OK and you can reconnect the vacuum line. If ATF drips out of the vacuum line, you need a new modulator. Put a fresh gasket on the pan and reinstall it. Fill with fresh Dexron. Be careful not to overfill as that can be as bad as an underfilled transmission.