Rear wheel studs failure

[IAN MEGSON]

Hi all. I have a 2001 transit 125/350 with commercial box body and twin wheels at each end of the axle. Pulled up on the motorway (just in time), to find only one wheel stud left out of six (rear near side wheel). I have removed the wheel rims and brake drum to find the studs have all failed flush with the bearing carrier hub. I cannot explain this problem other than that at some time the nuts have been overtightened causing the studs to fail. The remaining stud is a bit chewed up but still in place and I cannot see any evidence that it is about to fail. Has anyone ever heard of this fault and if so can you shed any light on the cause?
Thanks & regards, Ian.

[mobilevanman]

have you had tryes fitted recently as they can come loose and shear

[IAN MEGSON]

Thanks for your reply mobilevanman: No. I have done well over 1500 miles since I serviced the rear wheels and re-checked the wheel nuts after a couple of hundred miles running. I checked the offside this morning as a double check and they are all tight. The studs have all failed flush with the bearing hub, so at the back of the brake drum holes. All the fracture's look idenical and there is no evidence of shear stress (though its hard to be 100% sure as there are no studs to examine).
Are the nearside bearing nuts left or right handed thread (I cannot see enough of the thread)? Regards, Ian.

[mobilevanman]

nearside bearing left hand tread but it wont be a bearing problem to shear rear studs check hub face as if warped or ditorted wheel nuts can be overtightend to get it flush check inner face of wheel aswell as i have had distorted centres causing vibration (found and recified before any futher damage)

[shovelheadrob]

A common cause is when the spare wheel has been fitted, basically there is usually a bit of surface corrosion on the seat area where the nuts go, this gets compressed when you first tighten the wheel nuts but after a short time ( within 1000 miles ) the corrosion breaks down leaving the nuts slightly loose leading to stud failure. I have had it happen on my old Mk5 Transit & also on an American pick up, so now whenever I've had to use the spare I either clean up the seat area before fitting or, depending on the urgency at the time, remove & clean very soon after.