After seeing that my driver side running board had fallen off ,it appears that the running board brackets are intact and the board fell off the 3 support arms . Upon inspection , I suspect that each support arm secured 2 bolts , all of which rusted /sheared and each end had screws to secure the ends from flapping . The running board appears to be molded fiberglas , no structural metal was seen . Questions : what was the OEM method to secure the running board to the support arms ? Was there a hex nut imbedded in the fiberglas ? My boards have a rubber traction pad glued over the top of the board . When I peel back the traction pad , I do not see any hex nuts remaining in the running board . I thought that 6 bolts would pass through the running board and receive a locknut underneath . My concern is that this would cause a protrusion above the running board ( the hex head bolt would stick out and interfere with the traction pad ). Perhaps there was a hex nut imbedded in the running board and the bolt passed upward from underneath ?? Just don't know . Would like to drill out the remains of the sheared off/ rusted bolt remaining in the original salvaged running board and then re-tap threads for new bolts . What is the correct OEM bolt size ? OEM hex nut size ? It appears to be a simple nut/bolt application except for the lack of structural steel within the fiberglas running board . Fender washers may help prevent crushing the fiberglas but they would create a bump in the top side . Anyone experienced this repair so the top side does not have a bulge ?