Using mustang rotors for 4.5" bc

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Not a option for what is being done here. We are using the Ford rotors as they are very similar to the dodge parts but allow for upgrading to the bigger 4.5" bolt circle (opening up rim choices) and allowing to keep the very good IMHO KH 4 piston calipers.


Actually it IS an option as they sell the Mustang rotors too for a
very attractive price. Sorry if I did not explain my previous post
well enough.
 
I`ve read an article or two on the idea of using 66 Mustang rotors on A-body Mopars that came with KH 4 piston disc brakes (67-69 for ex.) in order to take advantage of the 4.5" bolt circle they offer. Since both systems were made by Kelsey Hayes it doesn`t sound out of the question. I did some research and found that both share the same inner and outer bearing. The Mustang rotor is almost a 1/4" larger in diameter at 11.29" versus the A-body rotor at 11.09". I bought a pair of these rotors Bendix #141017 and took them to a local machinist. The rotors can be used if the rotor diameter is turned down to 11.09. Two other cuts must be made, the inner bearing race must be removed and the seat has to be cut down .271 deeper to allow the rotor to slide up on the spindle ,the seal cup must be cut to match. Neither the Mustang or Mopar grease seal will fit since the od on the Mopar seal is too small while the Mustang seals id is too large. I`m still searching to find the correct grease seal. I paid my machinist $60.00 for the work (took just a little over an hour for both) and the cost of the rotors was just over a $130.00 for the pair. Now I`ve got the 4.5"bc with 1/2" studs on my existing 68 disc brake spindles by using the Mustang rotors. I hope this will help somebody by providing another alternative for getting the big bolt pattern without having to (go to the 73 and up system and) change out everything.

I have a 72 Duster with the KH SBP and am interested in doing this swap. Anyone in or around the Toronto Canada area had the machine work done? How is it going with those who have done the swap. Any problems after use?
 
The only problem I encountered was with the area between the hub and the rotor. It's "as cast" and really rough in this area and it hit my calipers until I took a grinder to it and smoothed things out, after that all was good.
 
The only problem I encountered was with the area between the hub and the rotor. It's "as cast" and really rough in this area and it hit my calipers until I took a grinder to it and smoothed things out, after that all was good.

Thanks for the info. Which seal did you end up using and is it still holding up?
 
Here's what I bought:


RAYBESTOS 6004R Disc Brake Rotor and Hub Assembly F $41.85 (2) $83.70
SKF 16743 Grease Seals (Stock) $9.33 (2) $18.66
 
I have a 72 Duster with the KH SBP and am interested in doing this swap. Anyone in or around the Toronto Canada area had the machine work done? How is it going with those who have done the swap. Any problems after use?

Sorry I can't help you when it comes to recommending a machine shop in your area but if you read through this thread you'll find a few things that people have encountered with the swap. All things said and done it has been a relatively easy, inexpensive, and effective way of getting the 4.5" bolt circle while maintaining the KH brakes. The key to the swap is a good machinist.
 
Like many others, this is the set-up I've been looking for!
My 1968 Barracuda doesn't have the requisite disc-brake spindles, which I understand are a must have for this swap.
Has anybody determined what might be required to install the Mustang rotors on drum brake spindles?
 
Like many others, this is the set-up I've been looking for!
My 1968 Barracuda doesn't have the requisite disc-brake spindles, which I understand are a must have for this swap.
Has anybody determined what might be required to install the Mustang rotors on drum brake spindles?

I believe Hotrod USA or another one of those brake companies sell a kit that retrofits onto the 10" drum brake spindles.
 
Wow, I love this thread! I've been trying to figure out how to change to the big bolt pattern without changing the KH's disc brake set up for a while now. I will be doing this in the near future. Just wanted to say thanks for figuring this out!
 
Thank longgone for the 4.5 brake info just orded the rotors and seals today hope to have macheaned and ready to go next week . Next the rear brakes hope to have car out and pics for this summer car been awayand finished for 14 years.
 
Why couldn't the Mopar one be re-drilled with the larger pattern? seems like a lot less work than trying to find bearings and seals.


Chuck

If you do, it looks like this. I was uncomfortable with driving on these. The previous owner drilled, apparently couldn't find the proper studs so he used all thread and welded the backs. This is the better looking of the two. I actually changed the spindles to a 10" drum spindle and put the wilwood brakes on. But, I also bought the 66 mustang rotors and am going to have them machined. I'm going to sell the KH setup but wouldn't be comfortable selling something I wouldn't be comfortable with.
 

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So I decided to convert my car to 4.5 bolt circle and bought 2 Raybestos 6004R rotors. I was looking at the seal cup on the Ford rotor and most all of it will be milled off to match my Mopar rotor. So if the bearing race diameter's are the same why can't you just slightly bevel the Ford race dia. to match the Mopar race dia. and tap in the Mopar seal? Then you have the correct seal for your car.

If I'm missing something let me know. But it looks like it would work.
I took them to a machine shop and he wanted $300 to cut them. Need to find someone else.
 
So I decided to convert my car to 4.5 bolt circle and bought 2 Raybestos 6004R rotors. I was looking at the seal cup on the Ford rotor and most all of it will be milled off to match my Mopar rotor. So if the bearing race diameter's are the same why can't you just slightly bevel the Ford race dia. to match the Mopar race dia. and tap in the Mopar seal? Then you have the correct seal for your car.

If I'm missing something let me know. But it looks like it would work.
I took them to a machine shop and he wanted $300 to cut them. Need to find someone else.

Yes that could be done but I think it's just easier and less time consuming for the machinist to tap straight down into the hub to create the new race seat.
Yup Bob, at $300.00 that machinist you found must be quite proud of his work.
 
So I decided to convert my car to 4.5 bolt circle and bought 2 Raybestos 6004R rotors. I was looking at the seal cup on the Ford rotor and most all of it will be milled off to match my Mopar rotor. So if the bearing race diameter's are the same why can't you just slightly bevel the Ford race dia. to match the Mopar race dia. and tap in the Mopar seal? Then you have the correct seal for your car.

If I'm missing something let me know. But it looks like it would work.
I took them to a machine shop and he wanted $300 to cut them. Need to find someone else.

That's exactly how I did mine. I had the machinist turn the profile into the inner seat to accept the stock seal. Worked perfect.
someone should find the right machinist and make a couple dozen of these!
 
Here's a few pics of what I'm doing. I have it mocked up, just hanging off the bolts with the caliper centered on the rotor. I used feeler gauges to measure the gap, which is the same number that John used to cut his.
 

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I'm glad to see you guys taking this modification and expounding on it. Cutting the seal to match the original diameter is great. Please continue to add your ideas.
 
Ok solved the problem some are having with the rotor not fitting with the dust shield in there. The problem is the original landing for the mustang grease seal needs to be milled off and you'll have plenty of clearance between the rotor and the dust shield.

Now my question is: is the the outer diameter of the original Mopar seal the same as the outside diameter of the bearing race? If not, does anyone have the outside diameter of the Mopar seal?
 
Found a local machinist to do the work for $100 (both rotors), and Summit has Bendix rotors for $32.95 apiece (Bendix Brakes PRT1017).

For anyone in the Dallas area wanting to do this conversion, the machinist is:
D&S Tool (Curtis)
(972) 241-5263
 
Ok solved the problem some are having with the rotor not fitting with the dust shield in there. The problem is the original landing for the mustang grease seal needs to be milled off and you'll have plenty of clearance between the rotor and the dust shield.

Now my question is: is the the outer diameter of the original Mopar seal the same as the outside diameter of the bearing race? If not, does anyone have the outside diameter of the Mopar seal?

It is very close to the same. I just took a die grinder and beveled the seal seat a little just to get it started in the bore. Look at your old Mopar rotor, it's the way the factory did it.
 
I had a few problems I had to iron out to get them to work.

I had the problem with the rotor rubbing the dust shield like some other people did. I just took them off.

Next issue was the outer bearing would bottom out on the spindle with the rotor installed, leaving a small amount of play. I chamfered the bearing a little to get it to tighten into the rotor race.

The castle nut was to far in for the cotter pin to go through it. So I added another washer to move the nut out to where the cotter pin can engage the castle nut.

I have $96.00 in two rotors with free Amazon shipping.

I paid $50.00 for the machining cost. I took 3 weeks though.

I bought two inner and two outer bearings, two Mopar seals, and two spindle washers.
I have under $200.00 in it.
 
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