The Lincoln transmission?

I have a 93 Towncar,the transmission works fine when it's cold, but when i get it hot like on a long trip the the transmission jumps out of overdrive into 3rd and then jumps out of gear for a second and then back to normal.Any help would be appreciated!

That's a tough one given the information supplied.

Things to consider:
1993
Miles on trans
Service intervals
Time since last service

IMO, a 93 that's been serviced twice or more per year, will not display the symptoms you describe.
Check the TV linkage and connectors Clicky (http://www.coolcats.net/tech/troubleshooting/shift.html), Clicky (http://www.lincolnsonline.com/article52.html)
Consider, decide if rebuild is needed Clicky (http://www.lincolnsonline.com/article60.html)

Flush and maintain your trans. to extend it's usable life Clicky (http://www.lincolnsonline.com/article75.html)

Happy Holidays.

this will often happen if your kickdown (TV cable) is too tight. a little increased pressure on the pedal when cruising down the road hits the kick down and causes a temporary down shift.