Sometimes my tranny pops out of drive to neutral, but will go back into drive with no trouble. I also have noticed that it doesn't shift unless it is warmed up. Any ideas?

year, model? I know it really does not matter, unless of course you have an 87...

I thought all that was updated in my profile, I'll try to fix that again. She'* an 88 SSE. 95,000 on 2nd tranny.

have you changed the fluid & filter recently?

Do you regularly change the trans fluid? What color is the trans fluid?

did you get this second trans new or used or remanufactured?

Your shift linkage cable could be out of adjustment.
To check it put the car in neutral with the ebrake on and wheels chocked.
Then go under the hood and loosen the cable nut positioning the shift arm in the center click position. Then re-tighten.

tranny was in a 90 cutlass supreme sl I have. got it used and my mech flushed it, changed fluid, filter, and gasket. then i put about 5,000 more miles on it in that car before i got bonne.

Your shift linkage cable could be out of adjustment.
To check it put the car in neutral with the ebrake on and wheels chocked.
Then go under the hood and loosen the cable nut positioning the shift arm in the center click position. Then re-tighten.

So when I put it in neutral, the shift arm will be in the center pos.? Pull the cable tight after loosening the nut, then tighten the cable nut back in place. :?

Its more like gently moving the linkage arm until it finds the center notch position then tighten the nut. You should not have to pull on the cable at all.