Posted by Paul Cook in Kempner, Texas on Wednesday, December 13, 2006 at 19:46:02 :
In Reply to: Ok... say I can't figure it out... posted by Chris Davis on Wednesday, December 13, 2006 at 18:37:01 :
Yes, they do center the drum to the hub BETTER.
The screw in question is a flat head 3/8" - 16 thread machine screw and is 1 1/4" long. Part Number 133 906
The taper on the screw head matches the taper machined into the brake drum and provides exact alignment or CENTERING.
Actually, the diameter of the hole in the drum is slightly greater than the diameter of the wheel studs Part No's 924 628 (RH) and 924 629 (LH). Without these screws, the hub may be off center.
Simarly, the hole in the wheel is also larger than the diameter of the wheel studs.
This lack of centering is extended by the fact that the Budd wheel nuts have a flat area about 1/16th" wide and that flat surface can be tightened against the wheel instead of the nut's conical face mating with the conical surface of the hole in the wheel. Release all the lug nuts on a wheel. The wheel will drop down to rest on the wheel studs. Then, simply tighten the nuts and the wheel is significantly off center.
Now, go look at your wife's car. The lug nuts have a full length conical face that lines up (centers) the wheel when those lug nuts are tightened.
The reason we have so much trouble removing the drum retaining screws is that many folks tighten them excessively. Then they get some rust. They only have to be installed with enough torque to keep them in place while the wheel is off the drum. And as has been said many times, use anti seize compound when installing them.
Those screws are available at most real hardware, auto parts, and equipment stores. I keep enough on hand to replace half of them when I do a full brake job.
Follow Ups: