'77 280 SE auto transmission slipping
i recently purchased a '77 280 SE, and the transmission seems to be slipping. it's definately worse when starting from a stop or going up a slow hill, but recently it has also started slipping at highway speeds, then catches again.
i've checked the AT fluid, it doesn't look or smell burnt and is at the proper level.
this is my first AT car, so i'm at a bit of a loss for what to try next. i'm hoping i don't need to shell out the $ for a new tranny, as i just bought this car.
any suggestions? online troubleshooting guides?