I had the same problem on my 2002 Forest River Wildcat. There are some photos and info here:
http://bobbystuff.com/rv/76/broken-springs
The problem is the springs are exactly rated for the axle weight and the GVW of the unit is exactly the axle ratings (or tire rating if less) minus the pin weight. So going down the road you are close to your max weight ratings if not over them. So if you travel much something is going to fail on the suspension.
On my new 325SRX toy hauler, I replaced the electric brakes with disc brakes. I am very happy with them. I have 5200 lb axles. The only difference between 5200 vs 6000 axles are the springs and one bearing. My disc brakes came with the bearing for the 6000 axles. At this same time I decided to upgrade the springs to those for a 6000 lb axle. So now I have some spare weight capacity. I don't plan to load my RV any heaver but I now have some breathing space on the springs and axles.
Here is a write up and photos on the disc brake installation:
http://bobbystuff.com/rv/228/electic...ake-conversion
I replaced the trash Trailer Kings tires over a year ago when one of them exploded. That story is here:
http://bobbystuff.com/rv/192/another-exploding-st-tire
Bobby