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Whitworth Threads or Just Nuts!

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JimLaney

JimLaney

Senior Member
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Since my last post the wheels have been media blasted, primed, and painted with Ford silver wheel paint and clear coated. 5 tires (needed a spare), Kumho SOLUS TA11 Tire 155/80R13 79T mounted and balanced. In mounting the wheels on the car there were two studs that no nut I had would thread all the way flush to secure the wheel to the front right spindle. There are 33 wheel nuts and any of them would thread up snug on 14 of the 16 studs. Naturally this was not evident until mounting the last wheel. I tried cleaning the threads with a small wire brush to no avail. Using my SAE die set, I was unable to find any die that would even start on the threads of the studs in question. There is no visible damage to the nuts or the threads of the studs.

Rather than apply more brute force and ignorance to this problem a search revealed conflicting answers to the question of whether the thread pattern was different for Whitworth threads compared to SAE. Apparently there is a slight discrepancy when one goes over an inch in length. Having no Whitworth die to clear the threads on the studs in question, there seems to be no solution that will make it possible to remove the nuts on the side of the road if a tire change is ever necessary in the future.

Before tearing down the right front axle sub-assembly to replace the studs, does any one have a suggestion to cure this problem without forcing the nuts onto these two recalcitrant studs semi-permanently? Suggestions will be greatly appreciated.
 
Jim,
All the wheel studs are 3/8" unless someone has replaced a stud with a metric one. Try your extra lug nuts on one of the other studs to help determine if it's the stud or nut. Lug nuts can be bought at an ATV store.
Rut
 
That was my first thought, too. Probably a standard SAE stud has been replaced by a metric one--don't ask why, just one of the charming little things that happen to these cars. It's not a bad idea to have a set of thread gauges to figure these things out--I keep BSF, metric, and SAE in my toolbox.

BTW, it wouldn't be Whitworth, in any case. There's an outside chance it might be BSF. The BSF thread pitch is not the same as Whitworth. Head sizes are one step smaller; i.e., 3/8 BSF has a 5/16 Whitworth head. Both are very different from SAE.
 
And you won't find wheel studs that fit out cars at the Big Box Stores. A BF Hammer will usually pop the stud right out. Work I usually do on the bench rather than on the car.
 
Thanks for the help! My thread gauges were all thin aluminum so I just got, in the mail, my set of screw in thread sizers.
Thanks for the tip on getting nuts at the ATV store.

The nuts all came off of the two MKIIIs that I have in the shop. I'm concerned that I may have damages to several trying to tighten them up. I'll check them.

On the bright side I finally had the time to get the rusty rocker arm assembly cleaned up and re-assembled. Tiny steps but in the right direction.

Thanks again.
 
While going through boxes and boxes of rat nests and other rat products, I found two chrome (aftermarket) wheel nuts and on a lark I tried them on the wheel studs that seemed to have buggered threads... went right on. Don't want for all times but will work for right now.
 
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