The car maker provides, free of charge, a kit made up by Böllhoff, which consists of 10 M14 x 1.5mm HeliCoil® inserts plus reduced diameter shank drill bits. The damaged holes are drilled out and then tapped with a reduced diameter tap. HeliCoils® are then inserted into the existing tapped holes to render them secure. There are two Helicoil® per trailing arm and two arms on each car.
The original HeliCoil® wire thread insert is a fully formed insert that is significantly larger in diameter in its free state than the hole that it is intended for. It has to be pre-wound using an installation tool prior to fitting the connector screw or bolt and then when it is in position and the tool removed it expands, like a spring, to fit precisely into the tapped hole providing a hardwearing screw thread with the greatest tensile strength - greater than the original tapped hole.
Benefits include good corrosion and heat-resistance, wear-free in operation, reject recovery, uniform load and stress distribution, easy identification even when installed (by using colouring or surface treatment). The HeliCoil® is available in different variants for very different requirements and the components are available in both metric and imperial dimensions.
To date, in excess of 200 HeliCoil® kits, together with reduced diameter shank drill bits, have been supplied to dealerships.
