P18 Boom outhaul car problem

Hello - I realized not long ago that the nylon wheel that's part of my boom out haul car on my P18 is cracked (half is basically missing). I want to replace it but see no way to do that. the pin going down the center of the wheel appears welded in place and, even if got the car out of the boom, i still could not remove the pin although i guess i could try to find an entirely new car with a good wheel to reinstall. Does anyone know how to fix this without obtaining a new car. Attached is a picture of my car. Thanks for any assistance.
Michael
http://www.thebeachcats.com/gallery2/main.php?g2_view=core.DownloadItem&g2_itemId=119351&g2_serialNumber=3
That is not your main problem. These plastic blocks on outhaul cars & H-16 & P-16 cheek blocks on side of mast were not expected to last 35 yrs. Live with the pulley shaft & lubricate the hell out of the car itself. Pete