Topic: disc rotor wear limit

[Brian Conway]

 author=sgibbs
Who makes the best repop rotors these days? Checked mine today and they are at .775

or, Brian maybe you want to see those rotors go to good use on my car?

As Bob points out the C5ZZ rotors may not be your best choice.  NAPA sells what appears to be a rotor with these same spec's, is affordable, and may be more in line with your needs.  Brian

[sgl66]

Thanks Brian,

No great rush to replace as I drive it less than a tank of gas every year. Will add to my list of parts to source, or maybe someone will start to repop a better version in the future.

Also sent a pm

[preaction]

Do the rotors have a date code on them ? I saw that there is on the rear drums but never gave any attention to the front rotors.

[1967 eight barrel]

 You can still get the original style rotors. It uses the original disc brake hub, which you'll have to press the wheel studs out to separate the rotor from the hub. Part Number is: 6004RGS. They are available via OReilly.
Nominal is: .0810 Minimum thickness is: .780. Runout is: .002.

I am trying to figure out how to restore the hub being they have been glass beaded and painted Eastwood's Detail Gray.
Here are pictures for reference.

I hope this is helpful.
                                                                             -Keith

[Bob Gaines]

You can still get the original style rotors. It uses the original disc brake hub, which you'll have to press the wheel studs out to separate the rotor from the hub. Part Number is: 6004RGS. They are available via OReilly.
Nominal is: .0810 Minimum thickness is: .780. Runout is: .002.

I am trying to figure out how to restore the hub being they have been glass beaded and painted Eastwood's Detail Gray.
Here are pictures for reference.

I hope this is helpful.
                                                                             -Keith

Once you press the studs and hub back on to the new rotor you will have to have it turned to true it up.

[1967 eight barrel]

Bob:  There isn't much meat on these. .030 and they are at minimum spec. I think I will check the hub for run out while I'm at it. I was going to buy new hubs, but I don't think the drum hubs are the same as the disc.
                                                                                                               -Keith

[67gtasanjose]

Bob:  There isn't much meat on these. .030 and they are at minimum spec. I think I will check the hub for run out while I'm at it. I was going to buy new hubs, but I don't think the drum hubs are the same as the disc.
                                                                                                               -Keith

With new bearing races installed, you can machine the hub sufaces on a brake drum lathe. (against the disc and the surface facing the wheel)
Naturally, you should refinish the  cast iron look of the hub before machining.

[1967 eight barrel]

Richard, have you had them done before on a brake lathe?
                                                             -Keith

[67gtasanjose]

I have done one of mine already (I own a brake lathe)

I made a hub adapter for straightening my Styled Steel Wheels on (wheels needed to be hub-centric). Not a difficult task, just separate the rotor and center the hub using the brake lathe's wheel bearing adapters, not the "cone" adapters. If memory serves, I used the rotor cutting head, cutting only one face surface at a time.

[1967 eight barrel]

Richard,
All went well. The hubs were returned to the "as cast" hub, and they machined the face of the hub before I installed the new rotors onto the original K/H hubs.
The first place I went tried to tell me that the stud holes would damage the brake lathe cutting tool. I asked it they turned drilled and slotted, which they did. Sometimes people aren't too smart.

                                                                                                                     -Keith

[67gtasanjose]

Richard,
All went well. They the hubs were returned to the "as cast" hub, and they machined the face of the hub before I installed the new rotors onto the original K/H hubs.
The first place I went tried to tell me that the stud holes would damage the brake lathe cutting tool. I asked it they turned drilled and slotted, which they did. Sometimes people aren't too smart.

                                                                                                                     -Keith

Ha! Kids these days!    Many places will not do things they haven't already tried once, fear of causing damage to your part, maybe?...but probably because they don't own the machine & want to stay employed there.
I owned the extra hub and the lathe so for me, it was an easy choice to try it. Outside the box thinking is much better than "canned BS".

This is a much better idea, IMHO than machining a new rotor. For whatever else it is worth, you could be able to test the new rotor for runout on the brake lathe BEFORE mounting it onto the hub and also check it AGAIN, after pressing the studs in (assembling it). That is my plan anyways.

I sure am pleased that somebody is offering the new replacement rotors again.(without being one-piece design), but I can surely see WHY they switched to a one piece design when the tolerances are so narrow.

[Bob Gaines]

Ha! Kids these days!    Many places will not do things they haven't already tried once, fear of causing damage to your part, maybe?...but probably because they don't own the machine & want to stay employed there.
I owned the extra hub and the lathe so for me, it was an easy choice to try it. Outside the box thinking is much better than "canned BS".

This is a much better idea, IMHO than machining a new rotor. For whatever else it is worth, you could be able to test the new rotor for runout on the brake lathe BEFORE mounting it onto the hub and also check it AGAIN, after pressing the studs in (assembling it). That is my plan anyways.

I sure am pleased that somebody is offering the new replacement rotors again.(without being one-piece design), but I can surely see WHY they switched to a one piece design when the tolerances are so narrow.

To clarify for those reading, it is the seperate rotor hat and not the complete two piece hub and rotor assembly that is again available. Agree it is a welcome change.

[Bob Gaines]

Richard,
All went well. They the hubs were returned to the "as cast" hub, and they machined the face of the hub before I installed the new rotors onto the original K/H hubs.
The first place I went tried to tell me that the stud holes would damage the brake lathe cutting tool. I asked it they turned drilled and slotted, which they did. Sometimes people aren't too smart.

                                                                                                                     -Keith

How true did the rotor /hub assembly turn out after truing the hubs and pressing the hat on?

[67gtasanjose]

You can still get the original style rotors. It uses the original disc brake hub, which you'll have to press the wheel studs out to separate the rotor from the hub. Part Number is: 6004RGS. They are available via OReilly.
Nominal is: .0810 Minimum thickness is: .780. Runout is: .002.


                                                                             -Keith

I just ordered a pair from my local O-Wowie's...Manager says they are the last two in the US!

I might be asking him more details once these arrive, (and confirmed same) See if there can be another pallet sent over from "The Orient" for other interested parties

I'll keep you posted

[1967 eight barrel]

How true did the rotor /hub assembly turn out after truing the hubs and pressing the hat on?

Bob,
it took .004 to true one and .007 for the other.