If your Volkswagen is equipped with a clamping bracket that fits around the steering bar or tie rod and secures the ball joint, standard nuts and bolts are not used. These can be metric threads, but with a pitch of 1.0, or metric fine threads. The original mirror arms and the fastener on the underside of the Split Bus vent window are also fitted with these fine-threaded M8 nuts.
On many Volkswagens, the bolts on the steering bar mountings or mirror arms have already been replaced by standard M8 x 1.25 nuts. Unfortunately, most reproduction steering bars and mirror arms don't use these special bolts and/or nuts either. Our standard gray-painted mirror arms are an exception to this rule, as they are the only ones to feature the correct M8 x 1.0 thread. Our range of vent windows and mounting kits use normal M8 x 1.25 nuts, or these M8 x 1.0 nuts only apply to original deflectors.
Volkswagen didn't choose metric threading for nothing, as it withstands greater forces and is less sensitive to dirt. Despite a great deal of dirt, loosening an original metric fine thread nut is no problem, whereas a metric 1.25 thread bolt will break or become brittle from all the dirt.
Always replace bolts and nuts in accordance with factory specifications. If steering bar mounting brackets are fitted with standard bolts and nuts, replace them with metric fine thread bolts and nuts. If you want them to be identical to the original, you'll need to buy new mirror arms painted gray.
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