Is this safe?
Is this safe?
(OP)
Hello everyone.
We recently had the (double) rear wheels stolen on both sides of our Transit twin wheel 14 seater minibus. We have obtained four second hand wheels and tyres but having fitted them inside edge of the inner wheels foul the brake calliper, not by much, but enough to be audible and to leave a deep score around the inner edge of the rim.
Another person obtained some washers and put them between the wheel and the hub flange, one 2mm thick washer on each stud was enough to provide sufficient clearance. However I’m not happy with it and recommending it isn’t used until new correct wheels are obtained.
My concern is based on the following theory. The wheels on the Transit get their concentricity by being a close fit over the machined flanges on the hubs. They get their lateral support (ie resistance to sideways forces caused by cornering loads) by being clamped (via the wheel nuts) to the machined face of the hub. My fear is that with washers between the inner wheel face and the flange face we no longer have 100% face to face contact. Instead, the washer becomes a fulcrum and with a vehicle weighing several tons multiplied by a G factor during cornering this will permit movement of the wheel laterally, resulting in either disintegration (crushing) of the washer, shearing of the wheel stud or loosening of the wheel.
Am I be over cautious? What do you reckon? Is it a valid theory?
Thanks for eading this.
We recently had the (double) rear wheels stolen on both sides of our Transit twin wheel 14 seater minibus. We have obtained four second hand wheels and tyres but having fitted them inside edge of the inner wheels foul the brake calliper, not by much, but enough to be audible and to leave a deep score around the inner edge of the rim.
Another person obtained some washers and put them between the wheel and the hub flange, one 2mm thick washer on each stud was enough to provide sufficient clearance. However I’m not happy with it and recommending it isn’t used until new correct wheels are obtained.
My concern is based on the following theory. The wheels on the Transit get their concentricity by being a close fit over the machined flanges on the hubs. They get their lateral support (ie resistance to sideways forces caused by cornering loads) by being clamped (via the wheel nuts) to the machined face of the hub. My fear is that with washers between the inner wheel face and the flange face we no longer have 100% face to face contact. Instead, the washer becomes a fulcrum and with a vehicle weighing several tons multiplied by a G factor during cornering this will permit movement of the wheel laterally, resulting in either disintegration (crushing) of the washer, shearing of the wheel stud or loosening of the wheel.
Am I be over cautious? What do you reckon? Is it a valid theory?
Thanks for eading this.





RE: Is this safe?
Mike Halloran
Pembroke Pines, FL, USA
RE: Is this safe?
Adding the extra spacers implies another risk. The 2 extra surfaces of the spacer will "set" when the wheel tightening torques are applied and since these 2 extra surfaces were not considered in the original calculation for the wheel torque there is also a risk that after a certain time the wheel nuts will get loose. I think you are doing the right thing to not use them.
dynatune, www.dynatune-xl.com
RE: Is this safe?
It is better to have enough ideas for some of them to be wrong, than to be always right by having no ideas at all.