Vibration

[ProfJohnL]

Having towed Caravans for over 50 years 6 berths ,4 berths, 2 berths I cannot see how a difference of 5kg on tow ball can cause a motor to vibrate only on acceleration. Being a motor trade involved family, I will still put the fault as being the tow car and the extra load being towed exaggerating the problem

The reported problem was not just when accelerating, As written its also when maintaining speeds of 45 to 50. So would seem to be when the engine was providing power as compared to coasting or braking.

I tend to agree that if the onset of any problem is triggered by only a 5kg nose load change, then that is far too sensitive, and it would be likely that if the speed were raised only by a few mph or the caravan went through a deep pothole the problem would likely reappear at the lower speed.

Quite simply we have no certainty about what is causing the problem, but in correspondence we have seen some factors come to light which are less than ideal. It's only right to make the OP aware of them.