Underlay work


Chassis work

Trailers’ chassis work, chassis reinforcements and structural alterations

Various chassis work and chassis reinforcements of trailers. Chassis alterations require guidelines in accordance with Trafi’s instructions, on how the alteration should be carried out. In other words, VAK may design and implement alterations easily and flexibly. We also complete e.g. the addition of axles to overall masses, when they undergo alterations.

We design the dimensions, masses and braking calculations. Brake alterations require a repair permit issued by Trafi. In terms of VAK trailers, it is worth contacting a VAK service point about alteration work. In this way, where the alteration shall be carried out, can be agreed in accordance with the alteration’s design and guidelines. Customers are provided a certificate about the alterations for the purpose of alteration inspections.


If the total mass and dimensions of the chassis change, then the addition of axles must also be carried out to correspond to the alterations. A fifth axle shall increase the trailer’s own weight by approx. one tonne, and the load size shall increase by approx. 3,000kg. The addition of trailers’ additional axles is favoured by the speed and affordability of the work.

Brake work

The brake work of trucks and trailers must be carried out carefully, therefore the equipment at our maintenance service points include brake diagnostics testing equipment. We always have valid A brake repair permits.