ARC have in stock these splined couplers, greatly simplifying fitting Apex style uni joints to factory rack splines. One end of the coupler is splined 9/16-36 to suit early Commodore, Cortina, Volvo, Jack Knight, Capri and Escort racks to name a few. There are 2 grub screws to secure the coupler to the rack pinion. The other end of the coupler is precision bored to accept 3/4 diameter tube/bar stock.