The shackles are pretty standard. If the shackle is worn thru, you need to replace all of them. Either install a wet bold kit or the "never lube" shackles and bushings. Either kits comes with thicker shackles....just make sure you replace the bushing in the spring eyes. Its not a hard job, just need 2 jacks and remove the wheels. BTW, always leave the trailer hooked to the truck when doing this. Bad things can happen if you dont. Most RV stores should have these or a spring shop. You could order them from Lippert, they installed the shackles.