Why carry out a steering axle conversion?
Fitting additional axles only takes place for one reason, to maintain legally compliant axle weights when using a vehicle for its intended purpose.
As with all chassis modifications the main reason why an additional steering axle would be fitted is to cater for a gap in the manufacturer's product range where there is no new standard line built product available to the correct specification or to increase the carrying capacity of an existing vehicle. In both of these cases the degree of difficulty encountered when installing the new axle will be dependent on the base specification of the donor chassis. Due to specialist nature of the axle required in this situation, depending on the configuration required the axle added may be manufactured by the chassis supplier or if circumstances dictate be sourced from an alternative supplier.
The base specification of the donor chassis will dictate the extent of the work required which, assuming the original wheelbase does not require modification, it could also involve the fitting of a chassis liner, an independent EBS module, modifications to the original steering arrangement or repackaging the ancillary equipment fitted by the chassis manufacturer to provide the working space required to accommodate the axle and its attachments.
The additional axle will be fitted with single wheels and tyres, however the choice of tyre size will ultimately be dependent on the customers operational requirements and the geometry of the finished installation.
Depending on the application, the additional axle could be fore or aft of the drive axle(s), or behind the original steering axle, which may itself have to be modified. The fitting of an additional axle could form part of a bigger conversion requiring other axles to be fitted, so this conversion should not be viewed as an either or option.