[working on it]

Ok, I give up.I've searched thru most of Chevelle Tech for a definitive answer, but can't seem to find one.The rotors for the '69-72 A-body single piston disc brakes have a 5/8" thick wheel stud mounting depth.If I use the Moroso 46160 wheel studs,with a .560 knurl,the knurled shaft only fills about 3/8" of the 5/8" space which was completely filled by the original studs.It doesn't seem to be as solidly mounted as it should be.Is this NOT the correct 7/16"-20 racing stud for this rotor?;or if it is correct, am I worried over nothing.Surely someone has already installed studs on these rotors before.Please clue me in!

[cjlandry]

Seems to me that the knurls purpose is to hold the stud in place while you're turning the nut onto it.

Once the wheel is clamped in place by the lug-nuts, the clamping force holds everything together, not the knurls.

I don't see a problem with the knurls not covering the entire span of the hole.

[72SSAbody]

Chad has it right.

Though I don't know why the call it knurles. Its actually splines. Knurles are what you see on a curling bar in the weight room (to keep a grip and not dump the weights on your feet...Ouch!!).

Do they list what drill bit to use if you are going from a smaller hole to fit the .560" "knurl"?

Joe

[Peter F.]

Is this the setup with rotor mounting behind the hub and if so, aren't they special studs for this set-up with a smooth part that locates the rotors and then a step with the splines? If so, I'd want the same thing on the replacements or find a really long spline that hits both holes tightly. Probably real hard to do.

Peter

[working on it]

I agreed with Chad that the clamping force is all that really matters, so I went ahead and bought the Moroso 46160 studs; besides that, I am no longer constantly changing tires/wheels once or twice a week (now that the chevelle is limited to strip only duty), so that once mounted they will stay put. As for installing the new studs; there are no instructions or suggestions in the Moroso kit, or on their website.The Moroso studs require a hole between .552-.559" to accomodate the .560 "knurl" . Since the rotor has existing stud holes of 17/32" (.53125),and my planned hole enlarger was to be either a 35/64" (.546875) or a 9/16" (.5625) drillbit, you can see that my plan will not work. However a 14mm (.03937*14=.55118") bit , and a little massaging, should enable me to press in the longer studs after all. And, the interior of the holes was accomodating a .555" knurl from the original studs, so it should be right in line with the reqirements. Peter- I've spent hours poring over various websites, wheel stud manufacturers' catalogs, actually measuring stock lugs from one make or another to try and closely match stud to rotor. No luck. I'll get it to work if I can find a 14mm bit. Or I'll take it to a machine shop (but I always like to do all my own work if possible, so that's my last resort).