noise from rear axle?

recently my montana has been squeaking when you go over a moderate to large size bump in the pavement. The squeak is from the rear suspension. The van has 84k and has the original shocks/springs in the back. It has the base suspension, not the leveling air one. I plan on replacing the shocks soon, do you think this is the issue or does something else need to be greased or replaced? Thanks!

not real familiar with the montana but shocks would'nt be my 1st guess.alot of squeaks/groans are tied to a dry bushing.Good Luck