Since a lot of special tools are required for disassembling, adjusting and assembling the gearbox, and since three different gearboxes are installed on the models described, the work on the gearbox bulkhead is not described. We recommend that in case of serious damage, exchange the old box for a new one. However, you should be aware of the difference between the individual gearboxes in order to set the required one. Models are equipped with the following gearboxes: