Audi Audi RS5 2010-2016 Suspension Bolt Torque Specifications

Using the correct torque specification ensures the bolts are neither too loose (leading to component failure and unsafe driving) nor too tight (risking bolt stretching, stripping, or damage to the mounting points). Correct torque provides optimal clamping force for proper suspension performance and safety. For example, under-torqued lower control arm bolts could result in excessive movement and instability during cornering, while over-torquing hub bolts can damage the wheel bearing.

Over-torquing can stretch the bolt beyond its yield point, compromising its structural integrity. This can lead to bolt failure, thread damage, or even cracking of the surrounding components. For instance, an over-torqued strut mount bolt might strip the threads in the strut tower, requiring costly repairs. Additionally, over-torquing a bolt often won't result in more clamp force - past its designed torque level, the bolt will stretch and weaken.

Under-torquing suspension bolts will not create the necessary clamping force between parts. This results in joint slippage, vibrations, and premature wear. Loose bolts will often loosen further over time resulting in component movement or separation. A common example is an under-torqued sway bar link bolt that can rattle and produce excessive noise and wear. This will result in abnormal component wear and potentially dangerous handling.

It's generally recommended to replace critical suspension bolts, especially those that are torque-to-yield (TTY) or have locking mechanisms. TTY bolts stretch upon tightening and should not be reused. While not every bolt needs to be replaced every time, always inspect bolts for damage, and replace bolts after any significant load, especially in areas such as strut mounts and control arms. Refer to the vehicle's service manual for specific recommendations. Always replace self locking bolts or nuts.

Using an impact wrench is generally not recommended for tightening suspension bolts, especially to final torque. Impact wrenches often deliver inconsistent and inaccurate torque. They are fine for removing bolts or very lightly installing bolts prior to final torque with a torque wrench. Always use a calibrated torque wrench to achieve the correct final torque specification.

Unless specifically called for in the service manual, most suspension bolts should be installed dry. Applying thread lubricant or anti-seize compounds can significantly alter the achieved clamping force for a given torque setting, potentially leading to under-torquing, over-torquing or failure. If bolts require lubrication, manufacturers will state this, or may supply pre-lubricated bolts. Always follow the manufacturer's instructions.