Transmission wont engage after i slow down

[quote:72118554e1="Super_66"]1994 Mercury Sable, 3.6 engine over 150,000miles

transmission will slip ......i can drive for 3 or 4 miles, it clunks somtimes when changing gears (not always)....then it will work after cooling down??
i have oil in it, actually after i put oil in transmission was when it started acting up......
i have oil leak up right front of motor, im tracking it now to see where it comes from..???
helppp[/quote:72118554e1]

Are you sure you did not over fill it? When was the last time you serviced it?
Fluid and filter change every 30,000 miles or 24 months. Check fluid level with vehicle motor running gear selector in park with parking brake secure.