Land Rover Defender benefits from 'foolproof' fastening system
A high-strength pierce fastening system is achieving 'foolproof'
fastenings at a number of points on Land Rover's Defender series
vehicles. Profil M8, M10 and M12 pierce nuts secure engine mountings to
the chassis via heavy-duty adapter plates, as well as mounting all
variants of the rugged tow-hook and pintle assembly, which is subject to
NATO military specifications.
One of the advantages of using this system is that it easily meets 'late
configuration' requirements when matching the chassis to different engine
options. This is achieved by using a pair of handed adapter mounting
plates, secured to the common base chassis by ten M8 Profil nuts. Several
alternative fastening methods were considered for the engine mount,
including captive nuts and riveted fixings, but these were rejected
because of their inability to meet the restricted space envelope
requirements and the possibility of panel distortion arising in an area
adjacent to a visible edge.
Profil fasteners have also been used on Land Rover's latest Discovery
series vehicles, where benefits of vibration and fatigue resistance have
been achieved, largely by eliminating thermal distortions caused by
welding. Welded fasteners can also initiate corrosion centres, as well as
risking damage to finished or plated surfaces. Pierce fasteners avoid
these problems, as well as the inherent health and safety issues
associated with welding.
Six Profil M6 nuts and studs are installed on each of the Discovery's
inner door modules after the base panel has been powder coated. These
assemblies support window winder motors and mechanisms, and as they
operate in a designated 'wet' area, each fastener has to provide a
completely watertight seal. Examples of Defender and Discovery series
subassemblies that make use of the Profil system are shown here.