1984-Just started swaying side-to-side...

Have a 1984 Caprice with 80K miles. Is a daily driver, in excellent condition, no rust, never been hit or abused. Recently it has started to respond to "road bumps" with a lateral shake; literally, 2 or 3 completely horizontal rebounds. If this was vertical, I'd just replce the shocks. If it was a rolling wallow, I'd check the steering components as well as the shocks. Car has 1 testing rebound on all 4 corners vertically, and the ride height is good. Tires are 50% worn, all the same, all at 36psi. The only handling mod on the car is a rear sway bar, which really improved cornering feel. However that has been there for 10 years. All this just started a few months ago, and is consistent, most obvious at 60mph on straight roads. Quick visual inspection on underside shows nothing obvious, but what could this be? Ideas, tests and suggestions welcome!

Thanks!
MRK

Shocks. The rocking test does not reveal everything.

Shocks. The rocking test does not reveal everything.

OK, thanks! I had a brain booger - was thinking 1957 leaf springs and forgot about the 1984 control arms!

so did you check all the front steering components like the tie rods/idler arms ETC ? 80K the front control arms[no rust] should be like new]. how often do you grease the front end and what grease type is used ? did you do the front wheel bearings @ 30K miles ? lateral slop will be with these Items ..