OK, so the car is up in the air on jack stands, suspension on the rear is thus fully extended resting on what I'll call the "stop bolts" just behind the trailing arm pivot bearings. In this condition, when I grab the tire at the 9:00 and 3:00 positions and try to wiggle it there is zero movement. However when I grab it at 12 and 6 I can wiggle it up and down maybe 1/8 to 1/4" as measured at the top of the tire. The trailing arm is moving, twisting around the pivot point so to speak. Is this movement normal?
Before I jacked it up I tried pushing on the top of the tire with my foot, rocking things side to side to see if I hear any noise or see any movement, it seems solid.
The half shaft U joints are all fine, look to be new with the trailing arms, no lash and no side to side movement.
The drive shaft U joint at the rear seems to have a tiny tiny amount of play in it, it might be my imagination, it's so hard to get up there and feel it. Lash through the ring and pinion does not appear to be excessive, just a little slop there. In short everything about the driveline seems to be in decent shape.
Rolling the tires around by hand yields no pop, snap etc.
I'm stumped, this up and down twisting of the trailing arm bothers me though.
Again the rubber bushings everywhere are original and in awful shape, I guess maybe start there? I am a little mystified as to what keeps the trailing arm from rotating in the direction I'm moving the tire, there is the lower tie bar connected below the axle but what about the top side? Are the shims in the trailing arm meant to be tighter or something?