The durability and interfacial chemistry of adhesively bonded joints fabricated from clad aluminium alloys (2024-T3) has been investigated using the Boeing wedge-test geometry and XPS analysis. A silane, gamma-glycidoxypropyltrimethoxysilane (GPS), has been incorporated directly within the adhesive formulation, and the effect of four different silane concentrations, 0, 0.5, 1, and 2% w/w, have been studied. As expected, the durability of the aluminium joints depends on the silane concentration contained within the adhesive formulation. The mechanical tests carried out showed that a silane concentration lying between 0.5 and 1% w/w would be optimum for the aluminium joints investigated in this work. The failure mode was apparently interfacial but the XPS analysis showed that some fractures occurred partly within the adhesive. The calculations of the C/N ratios from small-area XPS analyses on the adhesive interfacial failure surfaces have provided an indication of the manner in which failure may occur. It has been found that a depletion of curing agent takes place at the region where failure subsequently occurs, leading to a reduction in the mechanical properties at this region within the bond line.