serious shaking at speed: front end? transmission?

[jbrush]

hi folks,

well, i've been away for a bit (from town, and from these forums), but i'm back with more symptoms from my poor beat-up old 84 automatic (that got in a crash six months ago).

one day, since it seemed like we had most things figured out, we packed up the van for a little trip. heavy with people and stuff, the van started wobbling alarmingly as it built up speed (around 30mph), but then got a bit better (up to around 50), but then as we got on the freeway it seemed suddenly like the tire had popped, or was about to. we pulled over, and the tires seemed fine, and there was no obvious malfunction. but we turned around and came home, of course.

on closer inspection, at home, i definitely notice some wear on the outside of both front tires. it's pretty significant, and i suppose it could be the cause of the problem, but it might also be a symptom. i've jacked up the car, and tried wiggling the wheels at 9&3 and 6&12 o'clock. wiggling side-to-side jiggles the whole steering mechanism, up to the steering wheel, but there's no obvious play that i can feel in any of the linkages or bushings. wiggling up and down produces a tiny amount of give and a sound, that seems localized to the wheel itself and doesn't seem to to be communicated anywhere. bearing in the wheel, maybe? on that front, both front wheels have a bit of friction as i turn them -- when i spin them they stop within a few rotations. is that normal? some of the bushings are worn -- see pic below. but maybe that's ok?


at any rate, i think i can rule out the major problem being the front end (which is a relief, since failure there can be life-threatening). right?

secondly, i've heard from a friend that the automatic transmission can wobble, causing a resonance. indeed, there is a wobble where the tranny connects to the driveshaft -- see pic below. the wobble is pretty big -- about an eighth of an inch. and transmission fluid seems to be leaking directly out of the connection. any ideas what might be causing this? how to fix it? (there's also some give where this connects to the chassis up above -- but there's some kind of rubbery boot there, so maybe it's normal?)

this wobble in the transmission seems a major issue. would love to get input on it.

thanks so much, in advance, for all the help (once again)!.
brush