I recently found that bolt laying loose in my under skid panel. I went to my local dealer and he said this was a known problem. I let them put it back in as I did not have a good way to get under it to try for myself. They found that the seal was bad. Replaced the seal and added Loctite to the bolt when they put it back in ... $173 They said it took them all afternoon because the also took the shaft out to replace the seal.