I have an '89 Skylark, 2.5l, with about 200K on it and about 50-60K on the transaxle fluid. When trying to leave work yesterday, I had no reverse unless I gave the car a push backwards and then it started to go. When I got home and checked the dipstick with the engine hot, it was at the top of the crosshatch marks. I don't get it other than the fact it'* almost acting like my '94 Dodge Spirit did after sitting a half year with a slow tranny leak in which I had to add a quart and a half of ATF to get it to go in reverse. Any suggestions? Thanks.

200k is about where a trans may let ya down.
Could be the valve body, pressure solenoid or clutches etc.
You could add a can of Sea Foam Trans Tune, and see if that removes some varnish, and gets it moving again.
Is the transmission fluid clean, does not smell burnt, and is still reddish/clear in color or?

The fluid looks like it should and doesn't smell burnt. Thanks for mentioning the Sea Foam treatment. I'm going to drop the pan and change the filter. I'm also going to try to capture all the fluid that comes out for reuse.

Should upgrade to Dexron VI in the fluid change.
Personally, I would not re use the current fluid, in fear of even the slightest contamination.