Hey boys. I drive a DAF XF 450 and sometimes pull a draw bar trailer which needs,ideally, be raised slightly at the front (at coupling point). Is it legal to run the tractor unit slightly higher at the rear?.?
As long as axle weights are OK, nothing says vehicle has to be absolutely level. Last 2 wagon and drags (with Moffett) always ran slightly nose down. Just be careful if you lift it too high it can throw the weight backwards on the trailer and affect the handling. Our prime movers had automatic lift axles on the 3rd axle which had to be disabled for this reason.
I don’t know about modern lorries with electric involved but certainly with automatic load sensing valve and manually controlled raise/ hold /lower valves in anything but set ride height position there is no air to the rear axle brakes .
it sounds as though it needs a visit to a workshop to raise the ride height and make “normal” level
Manufacturer sets the ride height for optimum braking and handling and for correct axle weightings too. So for that reason, I would run it at correct ride height.
There is also the spray suppression aspect of it too. Raised mudflaps and wings may put it out of range of construction and use regs.
Thefunkster:
which needs,ideally, be raised slightly at the front (at coupling point).
The real question is why? Instead of ■■■■■■■ about with ride height.
Spookily, a piece in the current IRTE magazine about wear/ damage to the diff, including long term incorrect air suspension.
I’d more inclined to raise the coupling channel a bit higher up the drop plates ,won’t take long with a mag drill .