Have a dual axle back track aw19 trailer, noticed some grease on the inside of the back rims. Guessin the rear inner seal may be bad. I wanna order 2 new hub assembly and rebuild these for spares. Anyone know which model I might need? On tie downs website for vortex hubs it shows the grease fitting on the outside of the hub on the back side. Can I order those and still use the grease fitting behind the screw on caps? Local xpress dealer was horrible to deal with and told me I’m sol for warranty since I’m the second owner. Thanks gents.