Hi Graham, One would think the wrong pinion or tire diameter change would cause it to be off by a consistent percentage, not a linear 10 mph. I would compare its accuracy at 35 mph and 70 mph before doing anything. If it's the tires, pinion, or any rotationally caused error, it should be only 5 mph off at 35 if it's 10 off at 70. Otherwise, perhaps leave well enough alone and get used to it. How, by the way, have you tested it? Chris in LA 67 Crown 78 NYB Salon -----Original Message----- >From: Graham Quimby <ghquimby@xxxxxxx> >Sent: Jun 11, 2007 8:44 PM >To: mailing-list@xxxxxxxxxxxxxxxx >Subject: IML: 62 Speedometer off by 10 mph > >Fellow Imperialists, > >The speedometer on my 62 Crown seems to be off by 10 mph at all speeds >(except 0). I have tested it at highway speeds (between 50 to 70 mph) >and it is consistently 10 mph faster than the actual speed I’m >traveling. The transmission and real axle are original. I have >P235/75R15 radials. I’ve heard that a different tooth speedometer pinion >may fix the problem since I have radial tires. I wanted to double check >with the experts on the list what size pinion I should order. > >Thanks, >Graham Quimby >1962 Caramel Crown 2 door Hardtop > > > > >----------------- http://www.imperialclub.com ----------------- >This message was sent to you by the Imperial Mailing List. Please >reply to mailing-list@xxxxxxxxxxxxxxxx and your response will be >shared with everyone. Private messages (and attachments) for the >Administrators should be sent to webmaster@xxxxxxxxxxxxxxxx >To UN-SUBSCRIBE, go to http://imperialclub.com/unsubscribe.htm > ----------------- http://www.imperialclub.com ----------------- This message was sent to you by the Imperial Mailing List. Please reply to mailing-list@xxxxxxxxxxxxxxxx and your response will be shared with everyone. Private messages (and attachments) for the Administrators should be sent to webmaster@xxxxxxxxxxxxxxxx To UN-SUBSCRIBE, go to http://imperialclub.com/unsubscribe.htm