Changes to wheel hubs

[Bob Phillips]

So in other words, the early vs late style front drums and caps are matched due to the different bolt size holding the caps on. If you wanted to change a truck from early to late style hubs ( or vice versa) you would need to change the drums and the caps together as a set. I do seem to recall (as per Grants comment) the the wheel studs on the back of a late model truck ( with flange) are longer to accommodate the extra width of the flange.

[Jacques Reed]

The sling caps are held on by the three studs part No. C 380304-S which are 1/2" dia with 1/2 UNF and 1/2 UNC threads either end. My NOS hubs shown have these drilled and tapped holes.

The front hubs on mine have both the small, tapped holes for the standard cap and the larger holes for the sling cap studs. One size fits all as often is the case so perhaps some late war trucks had either cap, or it was just to keep parts inventory down.

I put 1/2-13 UNC grub screws with Permatex into mine to seal the stud holes as my earlier truck should have the standard caps.

Cheers,