hi, i just fitted mine, not worrying about the position and have not had any vibration problems. one thing i would say though is i would stay well away from reconditioned vcu's. vcu's are sealed for life and contain silicone gel which can not be replaced. so reconditioned units from my point of view sounds like a shiny coat of black paint and new bearings but the most important part (the part that causes all the damage when it goes wrong "the silicone") is not touched. I would recommend somewhere like ashcroft transmissions who sell a brand new one for £370 complete with new vibration damper.....