Integrity of bolted joints is one of the most important issues faced by engineers designing a new vehicle. The work reported here summarizes efforts to develop a rear leaf spring attachment to a frame bracket. The job was done while trying to resolve incidents of joint loosening in a prototype truck. It was found that the bolt holding the joint together was underutilized due to the bracket being overly stiff and due to reinforcement placement.
This article considers compression-tension loads in the joint, defines efficiency of the bracket, describes related laboratory and proving ground tests and gives recommendations for the design of similar joints. The recommendations could be used for design of any joint containing a rubber bushing with an inner sleeve clamped in a bracket with a bolt including the following suspension components: upper and lower control arms, shock absorbers, suspension links, etc.