1998 and 1999 Windstar sheared off lug nut studs

[krewl1]

My brother who owns a 1998 Windstar was driving one day when the front passenger wheel suddenly fell off causing him to strike a telephone pole luckily noone was hurt but the cause was sheered off lug nut studs.While most would attribute it to improper torque specifications I know he is very anal at checking the proper torque of each lugnut when he does the work himself. I wrote it off as an anonamly.
Fast forward it to last week when my wife felt a little wobble in the right front passengar wheel and I found three sheared off lugnuts. While I never have used a torque wrench , I could attribute mine to non torque specs even though I have never lost a lugnut or had one shear off in over 15 years of being a shade tree mechanic.
Just wondering how many others have had this problem or been in my situation.

[cougarman]

The cause of studs breaking is overtorque or under torque. Anytime the wheels are removed, especially aluminum wheels, they must be retorqued to the proper specs , then after driving approx 200 miles, they must be retorqued again.

[12Ounce]

Proper wheel lug nut torque is very important. Unfortunately too many of the tire shops have not learned this and are still using (only) impact wrenchs to attach wheels.

If you have lost any lug bolts, or have any reason to suspect that they have been damaged .... replace the entire set ... not just the obvious ones that have already broken. I would only buy lug bolts from the Ford dealer.

Use a torque wrench. Sears (and others) will sell you one of proper range (0-150 ft lbs) for less than $30.

Too little or too much torque will both result in failure.

[DRW1000]

Originally Posted by 12Ounce

Use a torque wrench. Sears (and others) will sell you one of proper range (0-150 ft lbs) for less than $30.

In Canada "Princess Auto" had a 1/2" drive 0-150 ft-lb torque wrench for under $30 Canadian

[krewl1]

While I do not disagree that improper torque specs could of played a role in my lug nut failure, the fact that it happened to my brother also is where I was perplexed as I call him the anal torque wrench man. After further investigation I also found that on the NHTSA website they had so many complaints about the Windstars lugs shearing off that they performed their own studies but ultimately came to the same conclusion with the improper torque specs as being the cause.
I just found it very coincidental that in all my years that this happened on the same make and model while I never had or seen a problem like this on any other vehicle I have worked on.
To play it safe I replaced the entire hub and soon the other hub will be replaced to help the wife restore her faith in the car.

[12Ounce]

Did your brother buy the car new, .... or does it have any tire service history that he would not be knowleable of?

[krewl1]

My brother did buy the car brand new from the lot and always had it maintained to specs. When the accident occured the parts where all stock Ford parts.
Actually even after the accident the NHTSA took all his old parts and later issued the torque spec docs after they examind a few of the same cases involving the Windstar. So he was basically left wondering how it happened since he was carefull since things were done to Ford Specs.
This was how I became aware of other owners having the same problem. Even after he warned me I still bought a used 1999 Windstar but of course I have no clue as to its history which is why I became perplexed with it occurring to the same model of vehicle.
My post was basically to see if it had occurred to others or to make other people aware of it. Luckily noone got hurt by either experience but it was alarming none the less and it has soured a Ford fan from buying another.

[12Ounce]

That is puzzling. Perhaps the bolts were overtorqued at the factory or the dealership(?). I guess this would be the scariest scenario.