Leaf-Spring Rebuild question

[Trek-Cyclist]

Here’s a question:
Front leaf-springs on a W-22, the rear of the springs are mounted to the chassis using shackles. My question is: Do the shackles pivot with the rise and fall of the body?
I noticed that between the inside shackle and the leaf-spring itself there are what appears to be some type of shims, Do these need to move freely? I had all the pads replaced on the front leafs with Workhorse pads and the company that replaced them said all the bolts should be very tight, the rubber in the ends of the spring are poured in with a bolt sleeve. All mounting bolts should be tight and the rubber in the ends only allows the spring to travel within set limits. After a 2 hour drive however, something in the front area springs or shackles start squeaking with up and down or side to side movement. Could this be caused by not enough space between the inside of the shackle and the spring itself or should they be tightened more?
I also noticed that the shims that were in the lower spring and shackle are gone. When the service center remounted the leaf-springs they did not tighten the upper bolts on the shackle that are mounted to the body. Confused...

[speed racer]

For what it's worth, In my more than forty years of experiance in automotive/truck repair I have seen many times where they will tighten these bolts when the tires are off the ground and when you set the vehicle down it puts a strain on the rubber mount and inner sleeve causing premature failure. The proper way is to set the vehicle on the ground before tightening these bolts therfore centering the bushing at normal ride height so the inner sleeve is centered in the rubber bushing.

[DriVer]

Probably for the same reasons is why all the install instructions state to have the vehicles on all fours when tightening track bars and other chassis add-on equipment. I would expect that the spring tightening recommendation with the vehicle's load placed on the ground is a good option to pursue.