89 Auto 944

Hi, wanted to know if anyone knew a little about 89 automatic 944's. I have taken the rubber flywheel damper off of the drive shaft and in order to do that I had to take off a small retaining pin and a 1/4" metal bushing off of the driveshaft first. I think this pin and bushing was used as a one time install only when the car was built so the flywheel wouldn't shift around during the assembly on the assembly line. Do I need to install this pin and bushing when installing my new rubber damper? Or can I leave it out, I don't see where it would serve any purpose. Let me know if you can, I sure would appreciate any help anyone can throw my way. Thanks, J.R.