[Code of Federal Regulations] [Title 49, Volume 5] [Revised as of October 1, 2007] From the U.S. Government Printing Office via GPO Access [CITE: 49CFR393.89] [Page 432] TITLE 49--TRANSPORTATION DEPARTMENT OF TRANSPORTATION PART 393_PARTS AND ACCESSORIES NECESSARY FOR SAFE OPERATION--Table of Contents Subpart G_Miscellaneous Parts and Accessories Sec. 393.89 Buses, driveshaft protection. Any driveshaft extending lengthways under the floor of the passenger compartment of a bus shall be protected by means of at least one guard or bracket at that end of the shaft which is provided with a sliding connection (spline or other such device) to prevent the whipping of the shaft in the event of failure thereof or of any of its component parts. A shaft contained within a torque tube shall not require any such device. [33 FR 19735, Dec. 25, 1968, as amended at 53 FR 49402, Dec. 7, 1988]