I used an empi 5/8" 36 spline u joint (3149). It is split on one end. I used the split end to attach to the 16mm 60 spline rack. It fits right over (tight) and I used a high grade bolt to go completely through the u joint, then added a lock nut. I haven't had any issues. I just welded in a 5/8" 36 spline shaft into my VW steering column (fit perfectly inside the column ID).