49 C.F.R. § 570.63 Wheel assemblies.
Title 49 - Transportation
(a) Wheel integrity. A tire rim, wheel disc or spider shall have no visible cracks, elongated bolt holes, or indications of in-service repair by welding. (1) Inspection procedure. Examine visually for the conditions indicated. (b) Cast wheels. Cast wheels shall not be cracked or show evidence of excessive wear in the clamp area. (1) Inspection procedure. Examine visually for the conditions indicated. (c) Mounting. All wheel nuts shall be in place and tight. (1) Inspection procedure. Check wheel retention for the conditions indicated.
Title 49: Transportation
PART 570—VEHICLE IN USE INSPECTION STANDARDS
Subpart B—Vehicles With GVWR of More Than 10,000 Pounds
§ 570.63 Wheel assemblies.