1956 Dodge D500 Brakes - were they Chrysler or Imperial?
56D500boy
Posted 2020-01-15 8:15 PM (#593007)
Subject: 1956 Dodge D500 Brakes - were they Chrysler or Imperial?



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This is going to be a bit of a slog for you, the reader, but I think if you are curious/interested, you will find the conclusions rewarding (I hope)

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Sometimes in magazines with articles about the 56 D500, they will call the 12” brakes “Chrysler” brakes . Other times, they might call them “Imperial” brakes. They can’t both be right, can they?
The answer is going to be “it depends”. I think what it depends on is whether the 56 D500 was built for normal (“civilian”) use (including drag racing) or NASCAR-type track use, as we will see. And trust me, I will be discovering things along the way - just as much as you might be.

When the D500 was announced to the Dodge dealers in Bulletin J10 on Dec. 22, 1955, it only said that the brakes were to be “Twelve Inch Center-Plane Brakes – 37% Larger”. It didn’t say where they were coming from or what they were 37% larger than. On that basis, it is necessary to start digging in the parts catalogues to figure things out.

To be fair, that J10 Bulletin did say also that the wheels were 15 x 5.5K with the 4.5” bolt circle. That is the first hint that the brakes might not be Imperial because the biggest Imperials used 5.5” bolt circle wheels. More on this later.

See Bulletin J10 below

So we know that the brakes are 12” Center-plane but we don’t know for sure about the bolt circles that were used. Since bolt circles depend on the hubs being used, it might be handy to examine the definition diagrams for the brakes.

See Brake Diagram below.

As can be seen from the Brake Diagram, the hubs are called out as separate items from the brake drums. This implies that the brake drum/hub assembly was technically a multi-part composite, not just a single cast and machined piece of iron.

Chasing the drums as a separate item and looking for 56 D500 and then the various cross-applications, we get PN 1637 335 as the brake drum for both the 56 D500 front and rear (which plays to the separate hub possibility) *AND* a listing of other users of these drums including the C70 (56 Crown Imperial) and C73 (56 Imperial) and the S23 (56 Desoto Firedome), C71 (56 Chrysler Windsor) and C72 (56 Chrysler New Yorker) but not the sedans, the ESTATE WAGONS, i.e. the big heavy cars. That sounds good. I knew about the Windsor connection to the 56 D500 but not the estate wagon aspect. And the application list is the same for both the front and rear drums.

See 1637 335 call out below

So the possibility of calling the 56 D500 brakes “Imperial” is not ruled out, at least not yet.

Okay, what about the brake shoes? We know that the drums were 12” center-plane. We haven’t discussed width yet but it was 2.5”. Normal was 2” wide so right away, that could be at least part of the touted 37% increase.
Looking for D500 brake shoes in the 55-58 Mopar Parts pdf, I didn’t find anything D500 specific but I did find a 12” brake shoe, 1673 996 that required 8 shoes (2 per corner) for Dodges, Desotos and Chrysler/Imperials. Hmm....

See 1673 996 call out below

Not satisfied with that 1673 996 info, I had a look in my 56 Canadian Chryco parts hard copy and found a specific D500 brake shoe listing, i.e. 1673 993. This same number covers the D500, an S23 Desoto Firedome (including Estate Wagon) and the C70 and C73 Imperials. The 1673 993 is also listed for the rear brakes on the S24 Fireflite, the C71 Windsor/Newport (including Estate Wagon) and a C72 New Yorker. So really, not exclusively D500 and Imperial. Still some Desotos and Chryslers in the mix.

See 1673 993 call out below

So were there any D500s that got “Imperial” brakes? Maybe. I think the closest we get to that conclusion is for the D500 race cars that used the larger Imperial –based wheels with the 5.5” bolt circle hubs. So I went looking for the front and rear hubs for the C70 (56 Crown Imperial) and C73 (56 Imperial). I looked in both the 55-58 Mopar Parts pdf and in my 56 Chryco hard copy parts manual.

Looking in the pdf, I do NOT find a front hub specifically for the 56 D500 but I do find a 1635 353 that is for a D63 (Custom Royal) with 12” brakes. This was also used on the 55-56 Plymouths with a ½” thick mounting flange and the 1955 C67, C68, except Est. Wgn. and C68-300 Chryslers . Checking the 56 Chryco hard copy, I got a direct hit on the 56 D500 front hub with a 1633 046 PN. This same PN was used by both the Canadian and US built Desoto S23 and S24 and the Chrysler C71 and 72 (Windsor/Newport and New Yorker, respectively). Nothing to do with Imperials. It’s not looking good for “Imperial” brakes on the 56 D500.

On that same hardcopy page, I saw both the C70 (Crown Imperial) and C73 (Imperial) front hubs listed as 1671 346. This hub was also used by the Canadian/US S23 and C71 and C72 Estate Wagons. Looking back at the pdf, see that on the same page as the 1635 353, the same 1671 346 shows up as the front hub for the S23, C71 and C72 Estate Wagons and the 56 C70 and C73 Imperials and the 57 Imperial (IM) and 58 Imperial (LY1). The nail is almost in the coffin.

See Front Hub listings below

On to the rear hubs to see if there is anything to redeem the “Imperial” brake idea.

Good news, a direct hit on D500 in the pdf: Rear hub, 1633 048. This is shared with a bunch of 56-58 cars (none of which are Imperials): LP2, S23, C71, C72, except Estate Wagons and the S24, C75, C76, LCI, LC2, and LC3. On the same pdf page, the S23, C71, and C72, Estate Wagons and the C73 Imperial all used the 1633 049 rear hubs. Not sure why but the C70 Crown Imperial did not share in those reindeer games and had a separate listing for a 1633 058 rear hub.

These rear hub PNs are all confirmed in the 56 Chryco hard copy.

See Rear Hub listings below

While I was out shovelling snow (in Vancouver BC!!) I had a revelation: Based on the above, I think you could only say that your 56 D500 had Imperial brakes if you could take a front drum/hub assembly and slap it on your D500 front spindle (knuckle). The answer, I think, is no. The D500 knuckles are PNs 1633 060 and 061 whereas the Desoto and Chrysler Estate wagons and the C70 and C73 Imperials have a different number: 1671 332/331. On that basis, D500 brakes are definitely NOT Imperial brakes and really not even Estate Wagon brakes.

See D500 Steering Knuckle listing below

And here comes the final blow to the "Imperial" brakes "theory" (at least for the non-NASCAR D500s):

In order to use an Imperial brake drum, you need the Imperial steering knuckles. *AND* in order to use the Imperial steering knuckles you need the 1618 064/065 Imperial (C70 and C71) steering knuckle supports (same as the Desoto and Chrysler Estate Wagon steering knuckle supports). So where does that lead the non-NASCAR D500s? Turns out that they used the 1618 060/061 steering knuckle supports, which as it happens is also the S23 and S24 Desoto and C71 and C72 Chrysler non-Estate Wagon supports. Therefore, it is pretty safe to say that the non-NASCAR D500s used 56 Chrysler (or Desoto) car brakes.

See 55-56 Steering parts Diagram and 2-03-23 Steering Knuckle Support parts listings

So what are my conclusions? I trust that you have figured them out by now and I am just re-stating the obvious:

1. The normal non-NASCAR type racing 56 Dodge D500s did NOT have “Imperial” brakes. They did have brakes with the same drums and shoes as the Imperial but those same drums and shoes were also used by some Desotos and Chryslers (typically Estate Wagons), so not exclusive “Imperial”. The non-NASCAR D500 brakes were 56 Chrysler (or Desoto) car (not Estate Wagon) brakes.

2. The Imperial and the 56 Desoto and Chrysler Estate wagons shared the same front and rear hubs, presumably because they all used the more heavy duty 5.5” bolt circle wheels.

3. The NASCAR 56 Dodge D500s that ran the 5.5” bolt circle wheels (to be the subject of another post, another day) could be said to be running “Imperial” brakes – but only they could say that, not the street 56 D500s with 4.5” bolt circle wheels. It would likely also be fair to say that the NASCAR D500s ran Desoto and Chrysler Estate Wagon brakes but that wouldn’t be as “cool” as saying “Imperial” brakes. Ooo... Imperial brakes.

Hope you had fun slogging through this post. I think I had fun putting it together (but it was a lot of work chasing those part numbers).



Edited by 56D500boy 2020-01-16 10:56 AM




(Bulletin J10 12-22-55, D-500.jpg)



(BrakeDrumAndHubsDiagram.jpg)



(TotalContactBrakeDefinitionDiagram.jpg)



(56DodgeD500BrakeDrumsSharedWithDesotosChryslersAndImperials_1637335.jpg)



(56DodgeD500BrakeShoes_1673996_withCrossOvers.jpg)



(56DodgeD500BrakeShoes_1673993_WithCrossOvers.jpg)



(56DodgeD500FrontHubsNOTSharedWithDesotosAndChryslers.jpg)



(56DodgeD500FrontHubsSharedWIthDesotosAndChryslers_Hardcopy.jpg)



(56DodgeD500RearHub_1633048_SharedWithDesotoAndChryslers.jpg)



(56DodgeD500SteeringKnuckles_1633060_061.jpg)



(55-56FrontSuspensionDiagramFlaggingTheSteeringKnuckleSupport.jpg)



(56DodgeD500SteeringKnuckleSupports1618060_061.jpg)



Attachments
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Attachments Bulletin J10 12-22-55, D-500.jpg (126KB - 313 downloads)
Attachments BrakeDrumAndHubsDiagram.jpg (107KB - 314 downloads)
Attachments TotalContactBrakeDefinitionDiagram.jpg (159KB - 331 downloads)
Attachments 56DodgeD500BrakeDrumsSharedWithDesotosChryslersAndImperials_1637335.jpg (170KB - 305 downloads)
Attachments 56DodgeD500BrakeShoes_1673996_withCrossOvers.jpg (139KB - 307 downloads)
Attachments 56DodgeD500BrakeShoes_1673993_WithCrossOvers.jpg (178KB - 299 downloads)
Attachments 56DodgeD500FrontHubsNOTSharedWithDesotosAndChryslers.jpg (174KB - 289 downloads)
Attachments 56DodgeD500FrontHubsSharedWIthDesotosAndChryslers_Hardcopy.jpg (193KB - 287 downloads)
Attachments 56DodgeD500RearHub_1633048_SharedWithDesotoAndChryslers.jpg (176KB - 310 downloads)
Attachments 56DodgeD500SteeringKnuckles_1633060_061.jpg (181KB - 307 downloads)
Attachments 55-56FrontSuspensionDiagramFlaggingTheSteeringKnuckleSupport.jpg (123KB - 298 downloads)
Attachments 56DodgeD500SteeringKnuckleSupports1618060_061.jpg (181KB - 290 downloads)
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NicksGarage
Posted 2020-01-16 2:25 AM (#593017 - in reply to #593007)
Subject: Re: 1956 Dodge D500 Brakes - were they Chrysler or Imperial?



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I would assume they were Chrysler and not Imperial. If they used Imperial brakes, you'd need the larger bolt pattern wheels as well.
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StillOutThere
Posted 2020-01-16 9:54 AM (#593028 - in reply to #593007)
Subject: Re: 1956 Dodge D500 Brakes - were they Chrysler or Imperial?



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Only the 500-1 package race cars had "Imperial suspension" to include Imperial brakes. For the front that was just a matter of swapping out the Dodge spindles and brakes for the Imperial's. For the rear, Charlie Strang, Kiekhaefer's engineer had devised an engineering adaption to use the Imperial bearings, backing plates, shoes and drums on the Dodge axle. Same is done in my '57 Chrysler Road America competition model 300C rear axle.
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56D500boy
Posted 2020-01-16 11:13 AM (#593030 - in reply to #593028)
Subject: Re: 1956 Dodge D500 Brakes - were they Chrysler or Imperial?



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NicksGarage - 2020-01-15 11:25 PM
I would assume they were Chrysler and not Imperial. If they used Imperial brakes, you'd need the larger bolt pattern wheels as well.


Agree. Wayne adds more to that thought:

StillOutThere - 2020-01-16 6:54 AM
Only the 500-1 package race cars had "Imperial suspension" to include Imperial brakes. For the front that was just a matter of swapping out the Dodge spindles and brakes for the Imperial's. For the rear, Charlie Strang, Kiekhaefer's engineer had devised an engineering adaption to use the Imperial bearings, backing plates, shoes and drums on the Dodge axle. Same is done in my '57 Chrysler Road America competition model 300C rear axle.


Thanks Wayne. I woke up this morning with a thought that I needed to check the knuckle/spindle supports since the Imperial hubs/drums need the Imperial knuckle/spindle. Sure enough, the C70 and C73 Imperial (and Desoto and Chrysler Estate wagons) use a different knuckle support 1618 064/065. In contrast, the 56 D500 used the 1618 060/061 knuckle supports which were also used by the non-Estate Wagon S23 and S24 Desotos with power steering and the non-Estate Wagon C71 and C72 Chryslers with power steering.

As a side note, the non-power steering, non-NASCAR 56 D500s and the non-Estate Wagon S23 and S24 Desotos without power steering and the non-Estate Wagon C71 and C72 Chryslers without power steering used 1618 056/057 knuckle supports.

I've added this steering knuckle support info to my original post while the EDIT function is still open to me.

I think that the conclusion that the non-NASCAR 56 D500s did not use Imperial brakes but they did use non-Estate Wagon 56 Chrysler (and 56 Desoto) car brakes is a safe one.



Edited by 56D500boy 2020-01-16 11:14 AM
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StillOutThere
Posted 2020-01-16 11:24 AM (#593032 - in reply to #593007)
Subject: Re: 1956 Dodge D500 Brakes - were they Chrysler or Imperial?



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I believe your conclusion on the Estate Wagon brakes is correct.

I have not owned a Dash One car, of course, but did a lot of corresponding with Tim Dupont. You may know the IBM for his car has "Kiekhaefer car" penciled on it! As I recall the car has Imperial front springs also. I may be faulty on that. If not Impl, at least the HD option for Dodge. Think the rears are HD option station wagon leaf springs. Rear due to length difference between "senior cars" of Chrysler DeS and Impl versus the smaller Dodge /Plym.
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56D500boy
Posted 2020-01-16 12:45 PM (#593039 - in reply to #593032)
Subject: Re: 1956 Dodge D500 Brakes - were they Chrysler or Imperial?



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Wayne: I was already planning to do a separate post on the D500 springs. I have some info on that already. When I post that, I trust that you will bring your knowledge and comment. (Thanks).

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Powerflite
Posted 2020-01-16 3:05 PM (#593042 - in reply to #593007)
Subject: Re: 1956 Dodge D500 Brakes - were they Chrysler or Imperial?



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I think it would be better to keep it all in one post. All D500 stuff, that way it isn't scattered around the forum for anyone interested in learning about all the differences.
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56D500boy
Posted 2020-01-16 4:13 PM (#593045 - in reply to #593042)
Subject: Re: 1956 Dodge D500 Brakes - were they Chrysler or Imperial?



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Powerflite - 2020-01-16 12:05 PM I think it would be better to keep it all in one post. All D500 stuff, that way it isn't scattered around the forum for anyone interested in learning about all the differences.


Not going to happen. The thread would get too big and difficult to find things in it. My plan is to create maybe four threads dealing with 56 D500 parts, e.g. this one (Brakes), another for the springs (probably today), then maybe engine and then probably a D500-1 thread (there are three or four versions of the D500-1). AND THEN, I will create a single 56 D500 post with hyper links to the individual D500 info threads.

It will work better that way.

I had over 35,000 posts on an Audi forum and created similar one-stop shopping posts that linked out to all the component info. It worked well.

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56D500boy
Posted 2020-01-16 6:33 PM (#593057 - in reply to #593032)
Subject: Re: 1956 Dodge D500 Brakes - were they Chrysler or Imperial?



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StillOutThere - 2020-01-16 8:24 AM I have not owned a Dash One car, of course, but did a lot of corresponding with Tim Dupont. You may know the IBM for his car has "Kiekhaefer car" penciled on it!


Check your email Wayne. Copy of Tim's IBM card. Nothing penciled on it.

Moving on to springs.



Edited by 56D500boy 2020-01-16 6:34 PM
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300XMAN
Posted 2020-03-07 8:09 AM (#595354 - in reply to #593007)
Subject: Re: 1956 Dodge D500 Brakes - were they Chrysler or Imperial?


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Note: The 1956 Dodge D500-1s used the 8¾” Chrysler/Imperial carriers with Imperial internals and the 300Bs used the 95/8ths” carrier from the Dodge trucks, outfitted with Charlie Strang’s heavy-duty axle shafts. Carl Kiekhaefer thought nothing of demanding that custom gear sets be made up for either of the two carrier sizes. He hounded Chrysler Engineering’s Burt Bouwkamp about supplying a half dozen or so units in wild ratios and getting them to him ASAP. Problem was, the gear sets that ECK wanted did not exist and had to be engineered/developed from scratch. Carl, of course, wanted the units yesterday because there were usually 2-3 races on the schedule every week, sometimes on opposite coasts.

Edited by 300XMAN 2020-03-07 8:11 AM
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56D500boy
Posted 2020-03-07 10:48 AM (#595359 - in reply to #595354)
Subject: Re: 1956 Dodge D500 Brakes - were they Chrysler or Imperial?



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Thanks for that Karl. That "other" Carl (ECK) was a real peach. I bet that when he pulled out of racing in 1957 there were mixed emotions by Chrysler and Dodge staff.

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