Our Precision Rear Shift Coupling is an all-new part modified with new polyurethane bushings to remove all the play in it, and we add an adjustable drag nut so you can choose how stiff you want it to be. We start with a brand-new Porsche part, disassemble it, replace the internal plastic bushings with polyurethane ones, then install the custom shoulder bolt and nut with cotter pin for you. Adjustment of drag in the coupler is as easy as pulling the cotter pin, tightening the nut a bit, and putting the cotter pin back. Installation instructions for this coupling are provided in the 928 Workshop Manual. We also provide an Installation Supplement. The rear shift coupler can be accessed from under the car. Look up just past the torque tube and just in front of the transaxle and you should be able to see it as shown in the photo below. It may be covered by a large rubber bellows.