Replacement rotors for Bendix front brake system

[hemi71x]

Well your spindles, calipers, dust shields haven't been altered in any way, but you certainly have a one piece reproduction rotor on that car.
So it's obviously been replaced, when it last got a brake job.
If everything's braking well, as you state, put it back together the way it was, and don't worry about the spacer behind that bearing race.
Are both your inner bearings the same?
Do you know any prior history, mechanical repairs, on the car.

By the way, I correspond with a native Dutch guy from the city of Amersfoort (spelling?) over there in Holland.

 

[Wietse]

When ordering parts, not knowing any better i ordered the bearings that supposed to be in there and they fit on both sides. (A2 outer and A6 inner bearing) Both side races had to be pressed in, not too tight and not loose.
I do not know much history about the car, i do know there have been quite a few issues with suspension and alignment which i have attacked already by replacing everything.
The car brakes like a boss yes, so i am not concerned to drive it the way it is but thinking ahead of what to do in the near future.
Guess that is the way it was 10-15 years back to keep a Mopar driving in Europe you had to invent something and make parts work one way or the other.

Amersfoort is in the middle of the country, i live up north near the coast. (to drive there would take 1-1/2 hour which is considered far here)
Are you in the army or so? Working with fighter jets?
Because near Amersfoort is a military base, same near me is a military airport next to the city of Leeuwarden where, at the moment, US pilots and some more nationalities are having international training or so. (F-18's all over the place)

 

[hemi71x]

The man that i know in the Netherlands is a big military aircraft enthusiast, especially the old F-4 Phantom.
He found me on the internet, and became friends, throughout all these years.
I was in the USAF for 7 years, as a jet aircraft mechanic (crew chief) and spent 2 years in Germany, at the Zweibrucken, Air Base. 1974-76.
The Phantom in my signature picture was the Phantom that i was assigned to, but naturally worked all the ones on my side of the flight line.
I don't own any more Mopars in my old age, so i use that Phantom picture on the internet web sites.

 

[Wietse]

Nice to read that!
Funny how that goes you have similar interests and find each other somehow.

 

[miller]

Here's some evil thoughts, sorta backing the horse up...

I'll toss in, sounds like hemi71x, probably knows more on it than me. It's been a handful of years, since I did the brake conversion on my 64...adding disc up front. Used the old school parts, used parts off a 73ish A body, as what's in the parts needed list. All that was for 13 1/2", single piston disc brakes. Only 'new' parts I used, were the rotors, that Pep Boys carried. (Hate going into the Boys) Don't know if those rotors are still made, but, might be worth checking out.

You read the article I linked from AllPar. Just opinions. Just like mine, always figured the single piston the way to go. Those four piston were crap from the first. Others will say the opposite. Pick your poison!

Yes, you would have to change spindles out. Any junkyards there, with Mopars laying around? Just tossing ideas around.

 

[Wietse]

I think that, in a few years i might cross over to the disc kit side and replace all.
Braking power is ok for now and no parts leak or whatsoever.

I am still wondering why i measure a difference of 2cm between front wheels comparing when pulling a string across the rear tires?
Hopefully you know what i am on about?
To check the Toe in/out i pulled a string around the rear tires and going past the front wheels.
When the string sits flush with the rear tire, up front i measure an average difference of 2cm, like one wheel was installed with a spacer and sits more outwards of the car??

Yes, you would have to change spindles out. Any junkyards there, with Mopars laying around? Just tossing ideas around.

If you would toss a Mopar here on the junkyard you will never be heard of again

 

[miller]

like one wheel was installed with a spacer and sits more outwards of the car??

That would take a little checking, to figure out. Comparing both rotors, even different types, besides the basic measurements, the inner/outer bearings should locate the hub onto the spindle. That spacer you mention, probably throwing things off, too.

Guessing that car has been put through the ropes!

 

[miller]

Been too long, memory bad, wrong year

Here's a link...
https://web.archive.org/web/20160304105537/http://www.moparaction.com/Tech/archive/disc-main.html

 

[Wietse]

Been too long, memory bad, wrong year

Excuses, excuses....but you still remembered!!

Good article, will get a coffee and educate myself.
Hopefully in 20 years i'll be like you

 

[Wietse]

I was under the impression these Bendix 4 piston calipers were designed very well and still superior to the sliding, single piston design.
Almost no maintenance required and no chance on seized pistons, but engineering has not been standing still through time.

To save myself time to hunt down individual parts as mentioned in the article, i prefer to go for a complete kit like what Doctordiff offers, either stage 1 (11") or stage 2 (12")
Also, when this article was written kits like this probably were not supplied in the way they are now.

Thanks for all the info guys, this helps a lot making the right decisions.

 

[Billccm]

I agree that you should contact Dr Diff. He might be able to help you with replacement rotors, too.
I have his kit on my Road Runner, and very happy with the braking performance (and I had Wilwoods on my last B Body).

 

[Wietse]

I agree that you should contact Dr Diff. He might be able to help you with replacement rotors, too.
I have his kit on my Road Runner, and very happy with the braking performance (and I had Wilwoods on my last B Body).

Which kit did you go for? Stage 1 or 2?

 

[Billccm]

Which kit did you go for? Stage 1 or 2?

Stage 1.

 

[miller]

I was under the impression these Bendix 4 piston calipers were designed very well and still superior to the sliding, single piston design.

Apples and oranges. Both set-ups do the same dang thing. Just a matter of preference, and parts. A simple design, over a more complicated one, that has more parts in it, that can go bad.

I will agree though, getting the Dr. Diff stuff probably the way to go, since certain parts aren't being made. Back when I did mine, parts were still on the shelf.

 

[Dragon Slayer]

Your original Bendix rotor dia is 11.2". The KH 2 piece from 70-72 for B and E was 10.98. What is the dia of the passenger side one piece? In 73 they went to the one piece rotor. It was similar to the 70-72 other than the inner bearing going to A17. Which is not much of a difference in the race from the A-6, so the question is what is the real inner bearing size. Did some one get inventive and use a 73 KH with a A-6 bearing and a spacer.
The min thickness on that one piece says .94" which was the spec for the 70-74 KH disc. Not a Bendix type as you mention. The dia will help solve this.

 

[Wietse]

Thanks for that info.
I will be back home in 10 days, I will remove the wheels again, as I need to change the studs for some longer ones.
Then I can measure both rotors and see what I get.
Would not surprise me if any PO modified a later model rotor to suit this one, parts were not easy to come by years ago.

 

[Dragon Slayer]

One more thing and Jim may be able to provide an answer. But the hub on your 2 piece rotor, has a half moon cutout. My experience (Limited) is that that half moon is the 70-72 Hub B/E Hub. A square type was the A body. No cut out was 66-69 B Body Bendix. I do not know if this was a standard, or if it varied by manufacturer.

Now that rotor looks right with the tall hat area, but I wonder if someone mix and match stuff. I remember a buddy back in the mid 90s that had bought a charger with Disc brakes. He could not find replacements even back then.

 

[Wietse]

I did not know different models/years had different cut-outs.
Just had a look in the '69 vehicle service manual but the rotor shown looks different again with multiple "gaps" around the circumference.
It's quite clear someone did some mix matching on these brakes, but then again they do work well.

Pretty sure that i could get a set made by a good machine shop if i gave them a sample, but will not be worth it compared to upgrade the system to a Doctordiff kit or so.

 

[Dragon Slayer]

Here are some side by side pictures of the 70-72 KH Rotor and the 66-69 Bendix. The KH on Right, Bendix on Left. KH Rotor is rusty. The KH is a thicker hub with a beefer bearing area too. But many of the other dimensions are similar. It does fit into the Bendix rotor. I need to measure the bearing gap to help determine if the KH hub would put a Bendix rotor in the same relative position for the caliper. But it might. Notice the studs, the KH shoulder is 1/8" longer. This accounts for the thicker flange area where the stud goes through. The KH rotor has a shorter hat area, but it was a different set up with KH Calipers and a caliper adapter. The KH parts all had KH casting # and date codes. Know caliper. The Bendix I picked up at Carlise and supposedly came off a 68 R/T Charger. Had LH threads, and the only internal mark on the Hub was 318318 casting number. If you separate your 2 piece, we might be able to determine what is going on. And if the KH Hubs work for Bendix rotor, it may be a good alternative to matching up a more readily available Hub with the Dura Brake rotor. Would have to use the KH stud, but that would be it. Frankly I have a spare KH Hub. If that is the case, you could get it or one from another source, get a pair of the dura brake rotors and be set with a match.

 

[Wietse]

Looking at them pictures i am quite sure my 2-piece rotor is a KH.
The half round cut-out, the shape of the inner side of the hub (that sits against the rotor) is the same.
But how i understand the KH rotor is 1" thick, while the Bendix is .8xx".
In a picture i posted before i highlighted what looks like a lip from material that has been machined off to match the thickness.
Otherwise it probably will not fit in the rotor, or only with a set of worn pads.

Chrysler never changed the design of the spindles, so the bearings should be relatively in the same position.
Just the rotor might have moved slightly inwards/outwards, if the inwards/outwards difference fits in the .2" of rotor thickness difference you could machine the rotor to match. (probably what was done on mine)
Keep in mind the spacer i found behind the bearing is installed on the 1-piece rotor.
Bearing wise this 2-piece is a perfect fit, other then the above mentioned machining.

As you said, getting another KH hub, and a set of rotors to match i can stay with the Bendix callipers!
Looking at them rotors side by side, i think you can just slap a KH or a Bendix rotor on either hub and it will be centred with the calliper.
KH uses the same inner bearing so yeah just a set of matching wheel studs and it could be done. (only rotor thickness i doubt)