When I drive over cracks in the pavement I hear a "clunk" coming from the rear. I emptied out the trunk and it isn't anything in there, It sounds for all the world like the rear end body lifting off the frame but I'm sure it isn't that. It has to be in the rear suspension. How do I check if anything is loose in there i.e. bolts in bushings? Also, when I drive over washboard it tends to skitter sideways. Should I remove a leaf?

The "clunk" may be caused by the inlox bushings. I always thought it made a nise like base ball bats bouncing in the trunk.
The inlox bushing is the rubber encased bushing whth a metal liner and covering that is pressed into the rear spring front eye. The bolt that passes through ahd attached the spring to the front hanger must be very tight. It is torqued to 90 foot pounds.
When the spring is installed the suspension is to be at the normal rding hight so the rubber busing in in a no stressed position whenthe bolt is tightened.
Another area is the saddle that clamps the rear axle housing to the spring. If has excessive wear can cause noise and clutch chatter. To tighten the cap on the saddle clamp can be millled/filed to close the gap - like filing a connecting rod cap.

Gene, can all this be checked with the car jacked from the frame with the rear hanging?

Would be best to tighten or check tightness of the blt when at normal position.
The chattering when going around corners with bumps was some what normal with older cars, Ifond that if I put more than 30 pounds in the rear tires it got worse.
The loosness in the spring saddle would show up with the suspension hanging (shock link disconneced) and would be at the bottom when suspension hanging and to when sitting on wheels at the top.

What if I put a dead enemy in the trunk? Would that make the rear end more compliant?

Sounds like the spring saddle. I had one that wore so bad, it wore a hole in the axle housing. Very important to keep it greased.

Is this what you refer to as the spring saddle?

That's it. should be a grease fitting on top. The two half are bolted together. If there is play, find out how much with a feeler and take it off the joint.

The spring saddles could be your problem but also look at the shock absorber oil level or the link bushes, they will rattle for small bumps like you describe.
Tony

Oil level is good, filled them the other day. link bushes are new..

I spent half the night devising a procedure to check this. Tell me if this would work:
- Jack the car with rear wheels hanging.
- Loosen the u-bolts
- Check saddle for movement, if it moves , remove and repair clearances

And of course I will check the bolts in the front eye of the springs.

If this has never been apart I can guarantee you there is excessive clearance.

It has, and I'm sure you are right. I likely thought it was normal. we'll see.

Here's what they look like, there is definitely some clearance. there. The ones on my spare rear end look tighter.

Looking at the top 2 photos I suspect there is some wear in the saddles. If you support the car either under the spring or chassis let the axle hang free then as you watch lift the axle housing, I suspect you will see some movement. As a test lift the axle and try packing a strip of thin metal between the underside of the axle housing and and the top of the lower saddle, go for a short drive over a section of road you know causes the rattle, if no rattle the saddle is your problem.
Tony

I’ll do that before I take anything apart.