Front brake wheel stud/brake drum question
 

On my 52 F-1, I pulled the front drum off for a check-up. Putting it back on, I realized there were two sets of holes in the drum, both of which work. This is an original Ford-script drum, and AFAIK the hub and studs are also original.

I have always used the conical holes, because that's the way they were when I got it. But using those holes the drum doesn't center on the studs (it does center on the hub). Looking at the tops of the cones, it is clear the wheel or the lug nuts are bearing down on the cones.

If I use the flat holes, the drum just covers the shank of the studs (i.e., looks like that was the intent). The studs center the drum as does the hub.

I have a NAPA drum from the 80's and it has only one set of holes, and they are flat.

I can't think why Ford would make the conical holes unless the same drums were used on some other cars where they were needed. (AFAIK not the case)

Which holes would be correct? My inclination is that it's the flat holes. No guidance in the manuals.

Re: Front brake wheel stud/brake drum question
 

No idea why that would be, but I would use the flat holes. and make sure the nuts do not bottom out before the wheel is tight. Original nuts are missing a couple threads on the bottom to clear the fat part of the stud

Re: Front brake wheel stud/brake drum question
 

Studs go thru the flat holes.

No idea on Ford's reason for the other set; plus they are way too tight on the studs.

Had to use a hole saw around the studs a couple times to get stick drums off when someone put them on wrong.

Re: Front brake wheel stud/brake drum question
 

The studs are actually a loose fit in the conical holes, but that may be from the studs moving in the holes? (wallowed out?)

I assembled it using the flat holes, and it seems to fit better, torquing the lug nuts seems to go more smoothly.

Thanks for the replies so far.

Re: Front brake wheel stud/brake drum question
 

Agreed Ross, good stuff. I have mine on wrong for sure.

JB