I don’t know if this is oing to be any help to you but I drive an 09 plate 8 wheel Scanny tipper and mine has a what can only be described as a vibrating / whooing noise.
My mate who I work with had his new one a year before me (I had a 55 plate at the time) and I remember following him down the motorway for the 1st time…same droning noise i’m getting from my new one.
The only thing I can put it down to is the tyres…my 55 plate had different tyres to both the new ones and it never made the noise.
Obviously with yours being a unit if it is the tyres your going to hear it louder as theyre only a few feet behind you!!!
I can still hear mine doing it, but not as loud as the rear tyres are quite a way back on an 8 wheeler!!!
Try and follow a new one…you’ll hear it with your window closed!!
I’m pretty sure mine has Michelin tyres fitted, but i’ll check tomorrow and let you know…
Thanks for the suggestion Roj, that was checked but everybody who senses the resonance agrees it’'s airborne vibration consistent with the engine revs. Trouble is how can I prove it on paper? The only way I can describe the sensation I feel, is like being in my old house, when certain vehicles went by, the windows rattled, except it’s not the windows it’s my eardrums ! !
Bit of a longshot here, but ive had to change the two bearings on the cab torsion bar that sits behind the grill on a 7 month old scania once.The symptons exactly like you say and it used to give the driver a headache hope this helps tho.
The bearings had been damaged whilst going into the recess at either end of the bar ,they were changed as a bit of a last resort and thankfully it sorted it out its not a big job to sort out but i bet scania wont want to.When uyou next take it in tell them its started knocking around that area when going around roundabouts etc good luck.
