Suspension on truck/tractor unit

Question

Hello, i was wondering if anyone can advise if it is permitted for a heavy vehicle (6x2) truck/tractor unit that has air ride suspension as apposed to a steal suspension to tow a tri-axle trailer or similar that is on a steel suspension. ihave heard this is illegal but cannot find anywhere in the regulations that can confirm this. Am i breaking any South African road regulations by doing this. Thank you

Answer

There are no restrictions on the suspension of vehicles and the use of different types of suspension on different vehicles in a combination (apart of course from the serviceability requirements) – so the truck tractor could have steel suspension and the trailer could have rubber (or steel or air). The only requirement for suspensions is for semi-trailers where only one type of suspension may be fitted on the semi-trailer (either air OR steel OR rubber).