I'll like to share how I installed the affordable 11.75" fullsize Chrysler discbrake rotors on my '62 Chrysler NewYorker stationwagon.

My '62 Chrysler NewYorker stationwagon came stock with 12" drumbrakes all around. When I bought the car some 10 years ago, the brakes on the car where working fairly good. At least, in the city that is at lower speeds.
On the highways, you had be aware of the longer braking distance one would need because of possible brake-fading.
In the years, the brake fading got a little worse because the drums wore out more and now had a larger diameter than the brakeshoes were designed for. So the actual contact-area between shoes and drums became smaller and smaller as time went on.

Anyway, about 2 years ago, the wagon started to develop an issue with the right front drumbrake when still cold. When the brakes were applied ever so lightly, the rightfront wheel would lock up immediatly. One had to put the car in Neutral or reverse to get the brake to release again.
As this issue got more serious every time I got the wagon out, one day I decided I wouldn't drive the wagon again unless there was a discbrake system on it.

Since there are no good AND affordable discbrake solutions available for pre'65 Chryslers, I decided to make my own solution and got to work.

In the past I had already drawn-up an adapter for '63/64 Chrysler spindles, to take on the caliper-bracket from a '73 Chrysler caliper.
I re-used a pair of early designs I had made, which weren't good enough for the '63/64 spindles and decided to redrill them for the '62 and earlier spindle.


Here's some info and some mock-up pics of the setup and the work involved;

Since the original drums used smaller bearings, I created sleeves for the original drumbrake spindle, so the larger bearings of the '73 rotor would fit properly.
(Note: if you decide on using '69-'72 rotors, the bearingsizes will be the same as the drumbrake-bearings, so you wouldn't have to make sleeves for the spindles. But these rotors are higher in costs.)
The rear-sleeve is lightly pressed into the inner bearing-race and the smaller outer sleeve is pressed onto the spindle itself. The larger sleeve can still be seen in this pic;




Pic of the affordable '73 discbrake rotor




After the rotor was fitted properly on the spindle, I 'clamped' the caliper-bracket, caliper and brake-pads all together onto the rotor, and measured where and how thick the spacers would be needed to weld them to the adapterplate.
On the '64 spindles I needed 22mm thick spacers, but on the '62 spindles I found 30mm spacers were needed.
So I cut 4 pieces of roundbar down to that size, drilled and tapped them with 1/2"-20 thread for the caliper-bracketbolts, and finally tacked and welded them to the adapter-plates.

Here's the rough adapter-plate mocked up on the spindle with the caliper-bracket in place




One little snag I found when mounting the rotors, was that the original 4 spindle bolts would interfere with the inner rotor-hub.
Two options were possible; I could just go out and buy smaller headed bolts like Allen-head bolts, which would be enough to clear the rotor.
But since it was weekend and UNF/UNC bolts can't be bought that easily overhere, I decided to turn down the inner hub on the lathe slightly.
No structural material was removed, just 3mm around the inner hub, just before the hub's strengthening and cooling ribs ended...




Here's everything bolted into place...




The '73 caliper uses the same brake-hose as the original one on the car, so this was a simple matter of reconnecting it again.

The only issue with a swap like this is that one can't use 14" wheels anymore, since the '73 discbrakes were designed for 15" wheels to begin with. But I'll also doubt that if you're willing to do a 12" discbrake-upgrade like this, that you'll still be using the 14" wheels anyway.

To this moment I haven't exchanged the single pot master cylinder yet, but testing the brake system in my garage showed it 'might' work very well.
Ofcourse for added fluid-displacement and safety one should upgrade to a dual-pot master cylinder.

Do you have the dimensions for the sleeves that you press onto the races? If the 69-72 disc bearings are the same as the drum bearings they would allow me to use the 73 rotors on the 71 spindles I have or am I missing something here?

Kevin

I don't see why that couldn't work indeed. I had those measurements saved in my phone but I seem to have deleted them again.

Anyway, on the RockAuto.com site you can read the specs of the bearings used in '71 and '73 and calculate the required sleeve-specs needed. Very handy of them (assuming the specs are correct).

These are the bearing-specs I just found on Rockauto.com:


1971
BCA/NATIONAL Part # A2 More Info {Cone Length=0.475" Bore=0.75" Outer Diameter=1.781" Width=0.61 StoundOut=0.135" Cup Length=0.475" Cone Radius=1.046"}
Taper Bearing Set; Front Wheel; Outer

BCA/NATIONAL Part # A6 More Info {Cone Length=0.465" Bore=1.25" Outer Diameter=2.328" Width=0.625 StoundOut=0.16" Cup Length=0.465"}
Taper Bearing Set; Front Wheel; Inner
======================================

1973
BCA/NATIONAL Part # A16 More Info {Cone Length=0.475" Bore=0.8611" Outer Diameter=1.81" Width=0.61 StoundOut=0.135" Cup Length=0.475" Cone Radius=1.05"}
Taper Bearing Set; Front Wheel; Outer

BCA/NATIONAL Part # A17 More Info {Cone Length=0.47" Bore=1.3772" Outer Diameter=2.3622" Width=0.625 StoundOut=0.155" Cup Length=0.47" Cone Radius=1.203"}
Taper Bearing Set; Front Wheel; Inner
======================================

A quick math gives these specs for the sleeves;

1973 - 1971 = Sleeve thickness
Inner bearing: 1.3772" - 1.25" = 0.1272"
Outer bearing: 0.8611" - 0.75" = 0.1111"

Ofcourse you need to play with these numbers a bit if you want a press-fit on the spindles.
And most of all, double check EVERYTHING and also question and recheck everything I've typed here. An error is easily made ofcourse.

I also recall I had made a small ridge with a radius on the larger inner sleeve, to prevent it from moving out from under the bearing-race towards the center of the rotor hub. This would be a bad thing to happen ofcourse.

I actually stock the same inner bearing adapter.

The cheap and eay way to put discs on is to use the 73 and up F/M/J/B/R body spindle.

Same height as my 64 300's drum spindle. Same ball joint tapers. Only thing I had to mod was shortening the tie rods themselves. Evrything bolted in.

I also stock the conversion seal.

I buy them in bulk from a transmission parts warehouse. If I remember correctly, the part is actually a 700-R4 pump seal.

Do you have an adapter that will work for the outer bearing? It would be really cool if someone would put together a kit to install unicast rotors on pre 73 C-body spindles (hint hint).

Kevin

I'm thinking about making the outer sleeve. Do you think there is any kind of market for them?

Cass - Empty you PM box!

Got to be some kind of market. 73 spindles are hard to find because they are one year only but you can always find a 69 to 72. The only reason nobody uses the early spindle is the 2 piece rotor is 3X the price of a unicast IF you can get them. That being said you won't get rich but you should be able to package up a set of sleeves and the seals for an attractive $$ and still make a small profit. You could add this to your disc brake conversion kits using factory parts list. C-bodies are going to be the next big thing. (no pun intended)

Kevin

I know they are needing a brake kit the average guy can afford - the kit should work back to the late 50's (57) - when t bars started - no?

Now that I've seemingly succesfully have done this discbrake-conversion on the '62, I'm going to redraw/redesign the adapterplate so I can have it lasercut again just like the one I had done for the '64 spindle. See pics below of the '64 spindle-design I once did.

I will also go on and convert the '60 NewYorker now, and if the spindles are the same, also the two '57 cars I have soon.
I will however be using fixed Wilwood calipers next for ease of parts availability.

Well done and well written with meaningful photos. If you ever need a job be sure and call a few of the mopar mags.

After this post has run its course, I vote archives.

Just remember the New Yorker uses a different ball joint than the Newport 300 uses.First joints my kid got for his 62 were the C body types.Too big.Had to get the smaller B body type.That and on them you can just use the later type discs like the Volaries etc.A kid at Carlisle had that setup on his 62 300.Rocky

They are supposed to fit.I havent done thet swap on his 62 yet.The kid that had his done said everything fit right up.Have a setup from the Dart we scrapped and a 74 B body set I will try.He dosent want to do it yet as his 12 inch drums stop so well even at 100 thru the 1/4.Rocky

My intentions with this conversion was to use the stock spindle, without any modifications, so there are also no changes in steering-geometry, alignment issues or balljoint swapping.

I took the wagon out for a drive up and down the street today just to find out how the braking-system works with the original single-pot mastercylinder still present and also stock distribution-block.
Pedalpressure is pretty much the same as before and braking feels safe and secure again.

But, as expected, the rear wheels will want to lock up, but only during firm braking. Driving and braking like a granny stops the wagon nicely though.
Then again, a stationwagon has more weight over the rear-axle, so a regular passenger-car will have the rears lock up earlier I'm sure.

The current drumbrake mastercylinder mostlikely has a residual valve incorporated inside, so it will always pressurize the brake-system with something like 10 lbs of pressure. This is good for drumbrakes, but not for discbrakes, as this will cause them to run hot very fast.

So I will be installing a used alum. mastercylinder from a late '80s Voyager since I have one laying around. Perhaps the diameter is too large and will cause a firmer pedal, but that's something I'll have to find out with trial and error.
I'll also be splicing up the current brakelines and replacing the stock distribution block with a proportioning valve.

A Wilwood proportioning valve installed in the rear brake line will solve the lock up problem. Is this a power brake car? If so the single diaphragm booster may come up a little short on boost. A dual diaphragm from a later disc brake car would solve the problem. Otherwise a manual master cylinder with a 15/16 piston (if you can find one) will give acceptable pedal effort.

Kevin