Topic: disc rotor wear limit

[67gtasanjose]

Bob, did you see the strange inset on the rotor where the venting is on these?

                                                                                  -Keith

The inset on the edge I believe would be "material removal" for the sake of balancing out the machined casting.
I have observed weights inserted or welded on various "old school" rotors... again, presumably for balancing.

Now discussing the three older rotors I have on hand, two believed as original, factory installed on my car and a third donor (has CENTURY cast into the inside) which I purchased last year from a member of VMF, do not have this machining for balance. Instead, the ones thought to be original, have balance weights welded on. The one with CENTURY cast into the rotor, has no such weights and no such machining. From an engineering standpoint, I cannot see a way to "balance" a hub by itself very easily... however, after a hub would be pressed onto a rotor, I can easily see how the assembly could be balanced.

IMHO, THIS MAY BE WHY WE SEE ONLY ROTOR/HUB ASSEMBLIES available these days. Not just for the inherent defects of "runout problems" like we have been discussing, but also because the two would likely have been FINAL MACHINED for runout AND balanced "as an assembly" (at the factory or manufacturer).

My intentions were to replicate the factory look as best I can with these "Chinitas". Fortunately only one of the "Chinitas" I have obtained has this machining.

As far as the "balancing" issue goes, I will simply leave the rotor with the "groove" cut into it, in play at this time. I'm thinking the hub, by itself, will not contribute too much for any "balance" issue since it is so close to the center of centrifugal force. I will do the machining on both hubs (as previously discussed in this thread) & recheck the assembled hub & rotor for runout and if it is within factory service tolerances (.002"), leave them alone.

Since my local O'Reilley's manager said these were the last two in the country, I suppose having one a bit less than par will be as good as I can get at this time.

On another thought,

Keith, do either of yours do have these machined out areas?

I'm pondering asking if Corporate O-Wowey (my name for OReilley's) if they can make another bulk order of these...maybe trade one in for one without the cut-outs....or just cave in with the idea that Keith & I simply just "got lucky" getting the last two pair available.

[67gtasanjose]

I did not have them checked for run out prior to assembly, however, pulling the studs in, I would imagine has a huge chance of distortion. Be SURE to lubricate the splined area on the studs, it really does help in pulling them in.
                                                            -Keith

Reply to an older post in this thread:

It might be a better idea to "press" the studs in rather than "pull" them in. I have done both. I have also "pounded" the studs in a few times (many years ago, never since buying a press).

My usual method of setting the rotor & hub up in the press is using an old takeoff rotor positioned upright as a 'pressing fixture' and with the new rotor face-to-face with the old rotor & 'starting all studs' first using a brass drift and a hammer tamping them lightly into place, then pressing each stud one at a time till MOSTLY seated (rotor still floats a little at this point), followed by a final seating of each stud till they bottom out.

The final result should minimize any distortion but more importantly, not damaging the original studs either.

"Pulling" the studs in (in my experience) has at times 'stretched the studs' slightly, making the lug nuts thread poorly (unable to spin the nuts by using only fingers afterwards)

"Pounding" the studs in, even with a brass drift, just sounds very amateur...This choice of procedure can't be very good with such a low tolerance machined product.

[Smokey 15]

 /\/\ Great idea. What I wil do next time. I used the "pull" method when replacing just one broken stud, and I have noticed the " lug thread issue" when using an OEM style stud.  Otherwise I take them to a friend's shop where there is a press.

  WOW, "Imagine" that!

Hey John Lennon, be nice 
I could quote Supertramps Lyrics for "Dreamer", 2nd verse might fit here rather humorously...but I'll play nice
Love the play on words

You better play nice or I'm tellin' mom. 

[1967 eight barrel]

Richard, I assume you mean the unusual small flat places on the outside edge of the rotor? Yes, mine do as well. Only sharp eyes would detect the issue, as I was more concerned with the "Made In China" on the edge.  If someone else needed a pair of these rotors, let me know. I may have access to another pair. Did they give you 6004 RGS?

                                                                                                                                          -Keith

[67gtasanjose]

Richard, I assume you mean the unusual small flat places on the outside edge of the rotor? Yes, mine do as well. Only sharp eyes would detect the issue, as I was more concerned with the "Made In China" on the edge.  If someone else needed a pair of these rotors, let me know. I may have access to another pair. Did they give you 6004 RGS?

                                                                                                                                          -Keith

Yes, same boxes you showed.

I'll use my brake drum bar to turn down the outside edge with the "Made in China etc", so that is a really easy task. It might take several 1000ths off the diameter but will not reach come close to the brake pad contact surface of the face side.

(failed attempt to load up to 20 images) Ask me if you are interested, I'll try again

[1967 eight barrel]

I didn't have access to a press, however I had the tool for pulling the studs in. The reason they get stretched like that is two fold. 1. He-man doesn't lubricate the threads, the conical portion of the tool or the splines they are pulling in. 2. They are using an impact gun to excess. I marked the studs and the hub so when they were replaced, they went back into the same hole they were pressed from.
I DON'T recommend a brass drift to drive them in. I tried years ago with a three pound hammer. Not a lot going on there, but noise.

                                                                                                                                                       -Keith

[67gtasanjose]

I've been trying to get pictures to load. Let me try only one this time and see what happens.

Notice the counter weights inside of the vents?

[1967 eight barrel]

Rich, pretty sneaky! Interesting they weighted them in the cooling slots! I would imagine balancing them in the hub would nullify balancing period.


                                                                      -Keith

[sgl66]

Richard, I assume you mean the unusual small flat places on the outside edge of the rotor? Yes, mine do as well. Only sharp eyes would detect the issue, as I was more concerned with the "Made In China" on the edge.  If someone else needed a pair of these rotors, let me know. I may have access to another pair. Did they give you 6004 RGS?

                                                                                                                                          -Keith

For reference, 6004RGS can be translated to one of the following part #'s: 6004R, 18A1342 or 5406

5406 from Autozone...same rotor, different package and they have plenty in stock. It's not rocket science swapping these onto hubs in fact thats how most modern disc brake systems are today.

http://www.autozone.com/brakes-and-traction-control/brake-rotor-front/duralast-brake-rotor-front/238821_205733_4825/?checkfit=true#close

[67gtasanjose]

For reference, 6004RGS can be translated to one of the following part #'s: 6004R, 18A1342 or 5406

5406 from Autozone...same rotor, different package and they have plenty in stock. It's not rocket science swapping these onto hubs in fact thats how most modern disc brake systems are today.

http://www.autozone.com/brakes-and-traction-control/brake-rotor-front/duralast-brake-rotor-front/238821_205733_4825/?checkfit=true#close

Look again at the images of Autozone's rotor and the ones recently purchased at O'Reilley and the original example(s).

Function-wise, sure it will probably work just fine but IMHO, it looks even less like original than the one-piece type that had been typically all you could find in recent years.

[sgl66]

AZ probably using a stock photo, here's what's in the box

[1967 eight barrel]

On the contrary, most modern brake systems use a hub that is studded. You don't press the studs out to remove the rotor from the hub. You simply remove the caliper, the caliper bracket and the rotor slides right off the hub. The Mustang retains the hub to the rotor by the studs being pressed in from behind, which sandwiches the rotor between the hub and the stud flanges.
                                                                                    -Keith

[sgl66]

On the contrary, most modern brake systems use a hub that is studded. You don't press the studs out to remove the rotor from the hub. You simply remove the caliper, the caliper bracket and the rotor slides right off the hub. The Mustang retains the hub to the rotor by the studs being pressed in from behind, which sandwiches the rotor between the hub and the stud flanges.
                                                                                    -Keith

Yup and as you said, much easier replacement.

My comment was aimed more at the 2 piece vs. 1 piece rotor topic.

[1967 eight barrel]

Makes more sense that way. Commas and periods can be important.    I like the one piece unit as well, however it's not as it came from Ford, so as usual... We're back to doing it the hard way.. Press part, press back together and turn to true. JOY! 
                                                                 Keith

[67350#1242]

I have access to a set or two of Raybestos 2 piece rotors for 65-67.  These are old stock MADE IN USA pieces - no made in China to machine off.  Raybestos 6004 look identical to the C5ZZ Ford service parts pictured earlier in this thread - Century stamp and all.
Price $300 for the set plus shipping.  See pictures.
Please Email me at kthornell@cox.net
I will get back to you as soon as possible.
All available sold.......... Will repost if I can come across any more, Thanks...