I got some strange starter damage on track this weekend and was wondering if anyone has ever seen anything like this or has any theories.
After coming off track at the end of a session, I heard light zing and ticking sounds which were engine speed related. Just as I turned into my parking spot I blipped the throttle heard a light pop and the sound went away. I thought maybe I picked up some debris that was rubbing against a pulley, but I couldn't find anything on the ground. I left the car running and looked under hood and everything sounded and appeared to be normal.
When I went to start the car for my next session the starter gear did not engage the fly wheel so I loaded up, bump started the car and drove home [over 600 miles from Road America to Rochester NY]. When I got home I removed the starter and noted the last 4 mm of the gear was ground off as was about 1 mm of the housing face. This appears to have been machined by the flywheel. It would have had to move over 1/4" to do this. I plan to take some measurements from the flywheel to the mounting flange and will likely pull the tranny this weekend. Here's a picture showing the damage to the starter gear teeth as well as the surface that appears to have been machined by the spinning flywheel. By the way the car drove great on the way home, no vibrations, good power, etc.
After coming off track at the end of a session, I heard light zing and ticking sounds which were engine speed related. Just as I turned into my parking spot I blipped the throttle heard a light pop and the sound went away. I thought maybe I picked up some debris that was rubbing against a pulley, but I couldn't find anything on the ground. I left the car running and looked under hood and everything sounded and appeared to be normal.
When I went to start the car for my next session the starter gear did not engage the fly wheel so I loaded up, bump started the car and drove home [over 600 miles from Road America to Rochester NY]. When I got home I removed the starter and noted the last 4 mm of the gear was ground off as was about 1 mm of the housing face. This appears to have been machined by the flywheel. It would have had to move over 1/4" to do this. I plan to take some measurements from the flywheel to the mounting flange and will likely pull the tranny this weekend. Here's a picture showing the damage to the starter gear teeth as well as the surface that appears to have been machined by the spinning flywheel. By the way the car drove great on the way home, no vibrations, good power, etc.