1993 GM vibrations/rumbles shifting into 4th
vibrations might not be a strong enough word... as the title says, when i am accelerating and the car shifts into 4th, it feels like i am driving over a rumble strip. you can feel it through the whole car. sometimes it kind of feels like there is also a slight power dip while the rumbling is happening. i also get some similar sensations when it downshifts into 4th.
does anybody have any insights that go any deeper than "your 4th gear is chewed up"? is there anything i can do short of bringing it to a transmission place? though it is a 1993, the car has just under 70k on it, so i'd really like to keep driving it.