I’m about to fit a pair of rock sliders to my defender 90. The front end fits on the bulkhead to chassis bolt. On my vehicle, there are four washers on the bolt. None of the vehicles in the fitting videos I’ve found on youtube seem to have these. Can anyone tell me what the purpose might be? Presumably I need to remove and then replace them to allow the rock slider to align correctly, do I just put them back on before the nut goes back? Also, I haven’t found a specific torque setting for this nut, do I need to worry, or just tighten firmly? I’m a new member here, complete novice and may be being over cautious?!