Based on Pat's information about this, I decided to order the bolt, metal bushing and shackle kit for my 2017, Z18 rig that sits on the tandum trailer. The Z18 is a lighter boat so I opted to do without the new center rubber shock absorber. The bolt/shackle kit was $80. I was surprised how worn the shackle bars were the holes where the bolts got through were nearly twice the size that they should be creating a lot of slack along with all the creaking and popping in tight turns. The plastic bushing were almost completely gone as well. The new kit worked great. I used a couple of jacks and replaced one bolt at a time to get them all replaced. Trailer tight and quiet again. I'm sure this will help control tire wear as well. I'm still on my original set of tires and they look good with all even wear.
