Clunk on Rear Suspension - Replace with Softer Spring?

[TerrazaMan]

I have a 05 Terraza, similar to the Relay. I have a issue where there are loud clunks over bumps on the rear suspension.

My service advisor said I have two options, keep the original springs or replace with a softer, but with less capacity. If I use the new ones that won't clunk, I will lose the load weight of 600 pounds.

I do not plan to carry 7 adults very often. This may happen occasionally if needed. I checked the specs of the van, the maximum load capacity is 1457 pounds. So, with the newer springs, I will have only 857 pounds left.

Doesn't the automatic load leveling springs compensate when the springs are being compressed? Or going over max will cause problems even with auto leveling?

Thanks.