Is my leaf spring broken??

[ericpost]

Hi,

I new to the board and I'm also the proud owner of an 1972 GMC Jimmy with a bunch cool modifications. This was my first 4X4 build so I learned ALOT of new stuff.
So on to my question... Lately I've noticed a thumping sound when I turn my wheel back and forth, the thumping happened in both directions. Not knowing what it was I climbed under and had a freind start turning the wheel. After 5-10 minutes of watching we noticed that the thump was coming from the drivers rear spring shackle. It was caused by the middle (of 3) leaf sliding left and right and hitting the the shackle hanger. I also noticed the upper leaf had a rub spot from the middle leaf sliding forward and back when it travels over bumps. This was not the case for the passenger side leaf spring. Does this mean I broke a leaf spring? Also as a temporary fix can I run a grade 8 bolt thru the spring to hold it while road driving (not off-roading)? While I'm asking how do I tell the lift? I bought this truck with a lift but don't remember how much of one. I think it was a 3 inch kit but not sure, plus I wouldn't trust what the lift was from someone selling a truck.