Posted By Stephen D. Clarke Has anyone any information and/or experience of wheel loss from heavy goods vehicles, coaches or minibuses. The loss appears to defy explanation despite an investigation by competent authorities. Its a very worrying situation.

Posted By Stephen D. Clarke Many thanks for your response: Its a minibus, Mercedes Sprinter, 2 axles;the rear near side wheel came off while the vehicle was in motion;all vehicle checks, wheel nut indicators, vehicle servicing, wheel nut torqueing, torque wrench calibration would appear to be in order. Vehicle had been making a whirring noise and driver had checked carefully around and wheel nut indicators were then OK. He then drove slowly home and wheel came off within 5 miles.

Posted By Karen Todd Not that uncommon an event. I remember reading the coroner's comments from an inquest, and he said something along the lines of he was concerned that these incidents kept happening. Go to http://www.belfasttelegraph.co.uk and search for "wheel nut" and "van wheel" (just the words, not exact phrases) in the archives and you can read the cases for yourself (I think they cost about £0.50 per article). 2 in particular come up: 1) 29 January 2004 HAULAGE SECTOR PLEA FOLLOWING M2 FATALITY - The coroner conducting the inquest into the death of a Dundonald man, who died after his car was struck head-on by a van that came across the M2 near Sandyknowes, said the case raised serious issues for the haulage industry. 2) 8 June 2004 INQUEST TOLD CHILD (4) DIED AFTER CRASH - Loss of kit car wheel nut led to tradegy. As far as I recall, both of these accidents involved wheels coming off. Regards, Karen

Posted By John C Provide a bit of history and a bit more information, if you would please: Has the vehicle had any recent wheel tyre changes? When was it last serviced prior to the incident? Had there been any recent kerbing, is there any evidence on the tyre wall? Was it a nearside wheel that came off? Did the wheel come off after it lost the wheel nuts or something else, hub failure perhaps? How and when the the wheel nuts checked for tightness prior to the incident? How long have you had the vehicle? John

Posted By Alan Haynes For info [may not be relevant to your vehicle] Mercedes did do a 'recall' on Sprinters produced in 2000 for a brake imbalance on the rear wheels - see http://www.theaa.com/all...=Mercedes-Benz&makeId=C7

Posted By mark louch Wheel loss is a problem that has beset the commercial vehicle industry in the UK and beyond for many years. It accounts for up to 10 fatalities per annum in the uk, numerous injuries and of course financial loss. In the last three weeks there have been wheel loss incidents reported in the trade press, as well as a fatal incident in the national media. On a basic level it occurs because of a loss of clamping force (energy required to hold the wheel in place by wheel nuts). Once the clamping force drops below a certain level (170kN)it is possible that wheel nuts will loosen due to the stresses and strains of road use (principally vibration). How is this possible when most commercial vehicle fleets follow a rigorous torque/maintenance policy? Unfortunately the application of Torque is no guide to the actual clamping force achieved. There are many reasons for this, damaged threads, corrosion, dirt between mating surfaces etc. It is therefore true that many fleets believe they are achieving the correct clamping force by following IRTE guidelines for Torque, whreas in fact they are not. The daily checks that truck drivers are supposed to follow are very little defence against the problem. Even when wheel nut indicators are fitted they are little guide to the level of clamping force present. Locking the wheel nuts in place is the only way to truly prevent wheel loss as a result of vibration. A fuller explanation of this issue is contained on the website www.wheelsure.co.uk, including video evidence from an industry expert. Brake, the Road Safety Charity will be publishing a new leaflet on this subject in the early part of 2005.

Posted By mark louch I think it is impossible to be precise. If you look at the video on the website I referred to you will see how quickly it is possible for the nuts to loosen if clamping force is lost. In truth I think that indicators are almost meaningless. The loss of clamping force required to be potentially dangerous would not be visible to the naked eye, even if well trained and conscientious.They are really a means of showing that a fleet operator is aware of the problem and taking precautions. If you require further information I can point you in the direction of two advisers on fastener technology who advised the Wheelsure business prior to start-up. Ultimately wheel loss will continue unless there is a fundamental design change to the wheel/axle (highly unlikely) or wheel nuts are locked. Mark