Had a wet bolt failure on the drivers side rear leaf spring. Don't know how it happened but returned home from a trip to NC and I got a brake warning from my dodge. Trailer brake error. Leaf spring had crushed brake wiring between frame and leaf spring. I could not find a bushing so I picked up a bronze bushing and new wet bolt. I replaced the parts on continued to us my camper. One year later my tires are wearing badly on the inside and outside ribs. Today I pulled all wet bolts to check bushings. I also discover the springs had twisted so that the springs looked like a fan on 3 out of 4 positions. I loosened up the axle bolts and realigned the springs. The bushings were plastic but are now bronze. I need to replace 3 out of 4 of the plates on the shackles that connect to the rubber damper between the axles. The leaf springs had wore about half of the metal away. Heavy duty my butt. For saving 20 cents per bushing I got this mess and 4 trashed tires. Because of the bushing play there was almost 3/4 inch of play on the axles moving forward and backward with acceleration and deceleration. At least they used bronze bushings on the center carrier 4 out of 12.