C-body Dakota Front Disc Brake Swap

Brakes, Suspension, Rims and Tires

  1. Mr onetwo

    Mr onetwo Well-Known Member

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    Has anyone actually done this swap here? You can certainly get all the Dakota stuff cheap and I assume the Moog K719 ball joint must do the adaptation from the early UCA to the Dak spindle. I know this has been mentioned in passing but I wanted to start a new thread on it.If this works it would be a great way to have affordable all Mopar disc brakes for our old cars.All the photos came over from Facebook.The more comments or thoughts the better.

    dak swap 1.JPG

    61889356_2170011003095953_387377132084396032_o.jpg

    dak swap.JPG
     
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  2. Mr onetwo

    Mr onetwo Well-Known Member

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    here is a couple of screenshots of the prices on Rockauto

    rock auto - dak swap.JPG

    rock auto - dak swap 2.JPG
     
  3. traintech55

    traintech55 Senior Member FCBO Gold Member

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    Thanks for the information. Chrysler did us all a very big favor by staying with certain dimensions on suspension parts. One thing I do recommend is use the master cylinder from a disc brake Fury or Dodge from your year, (1970)? I am not sure if the booster is the same for drum and disc brakes in your year. Good luck.
     
  4. Mr onetwo

    Mr onetwo Well-Known Member

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    still begs the question...does this actually work?
     
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  5. Mike66Chryslers

    Mike66Chryslers Well-Known Member

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    I think it's odd that the person whom you're quoting above first says this is an easy bolt-on conversion and "all the math is done for you", then later warns that this is NOT an easy upgrade, there is tons of math involved, and he doesn't say any more to cover his butt against liability. :realcrazy: Would like more detail to know where the difficulty lies in this. Presumably it's in that the Dakota spindles have different caster and camber angles.

    IMO, a basic question that needs to be answered is, if you do this conversion and take the car to an alignment shop with a copy of the factory alignment specs from a 1973 Chrysler FSM, can they align it to that? (I chose 1973 since it's the last year that they used our basic front end, with factory discs and 15x6.5" wheels, so closest to this setup.) Or can/should one use alignment specs for a RWD Dakota?

    If it winds-up with positive camber, that's a bad thing, but could be corrected by fabricating shims between the LBJ and the spindle. Negative camber may be ok to a point. There's probably no easy way to correct the caster, if it winds-up being a problem. However, the poster says "No adaptors needed." which implies to me that no such shimming is required.
     
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  6. Mr onetwo

    Mr onetwo Well-Known Member

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    physical differences and alignment specs

    dak-fury differences.jpg

    merge_from_ofoct.jpg
     
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  7. Mr onetwo

    Mr onetwo Well-Known Member

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    I think he is referring to adapting the front sway bar, but I could be wrong.I have reached out to him for some clarification.Here are the specs for a 1992 D150 and 1973 Dodge car to compare.I am posting all this up in the hopes that an alignment expert will chime in.

    1992 D150.JPG

    1973 dodge specs.JPG
     
    Last edited: Jul 17, 2020
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  8. Davea Lux

    Davea Lux Old Man with a Hat FCBO Gold Member

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    I have not tried this conversion and do not intend to. The question I have to as is that the Dakota is a much lighter vehicle than a C-Body. Will the Dakota spindles support the extra weight, especially if the car is a big block that is going to be driven aggressively? These spindles are in the B-Body range for size as are the rotors. I also think that the alignment might get tricky as with dissimilar front end components, where the car will hold tires might make it handle like crap. My 2cents.

    Dave
     
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  9. pomonamissel

    pomonamissel Senior Member

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    i'm currently placing some dr diff viper caliper brake kits and 69-72 c body rotors (11.75 dia) on drum brake spindles on my b bodies .
    i'm set to convert my 65 and 67 c bodies to 70 and 72 disc brakes from other c bodies , but since the same rotors are used . i'm going to see what it takes to put the viper calipers on the drum brake c body spindles as well .
     
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  10. 1970FuryConv

    1970FuryConv Senior Member

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    If you price your time at $40/hour and factor in all the time for the tons of math and other alterations, it would be cheaper to go with a drum brake conversion kit.
     
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  11. Mr onetwo

    Mr onetwo Well-Known Member

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    I'm not sure I agree Dave, at least in theory.The curb weight difference between my 1970 Fury convertible and a 1996 Dakota Club Cab 4x2 with the same engine is 327lbs. 1973 B-body rotors are 10.97", 1996 Dak rotors are 11.37" and 1973 NY'er rotors are 11.75". Is 0.38" going to make any difference? NY'er wheel bearings are the same as B-body - 1.3772" while Dak wheel bearings are same as D150 - 1.4961"
    I just think that all this stuff is insignificant to braking performance for a street vehicle.Master cylinder bore size and brake hydraulic system balancing are much more important IMHO. I doubt very much there is any strength difference between a NY'er spindle and a Dak spindle.On top of that the Dak has bigger wheel bearings and ball joints.The more pressing concern is the alignment. This is of course all theory until it is put into practice.Everyone is entitled to their own opinion and proceed at your own risk.:poke::thumbsup:
     
    Last edited: Jul 18, 2020
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  12. Mr onetwo

    Mr onetwo Well-Known Member

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    Does anyone have a spare 1970 drum brake spindle that they would be willing to contribute to this discussion for comparison purposes? There is a pair of Dakota spindles for a reasonable price at a junk yard close by that I am going to pick up Monday.
     
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  13. '69FuryIIIConvertible

    '69FuryIIIConvertible Senior Member FCBO Gold Member

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    If you want drum spindles I have a pair I'll send you for the cost of postage, I was gonna pitch them in my trailer for scrap anyway
     
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  14. Davea Lux

    Davea Lux Old Man with a Hat FCBO Gold Member

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    If you can make it work, all the power to you. Let us know how this progresses.

    Dave
     
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  15. stubs300

    stubs300 Senior Member

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    My big question is I would be worried about the caster angles being in the + side compared to the -1*. I wouldn't want to deal with that hassle.
     
  16. 1970FuryConv

    1970FuryConv Senior Member

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    @Mr onetwo I agree with Dave. If you can make it work, more power to you. Obviously, I like 1970 Fury III convertibles and would like to see as many as possible of the 1952 convertibles originally produced staying on the road. I used front disc brakes from a 1970 Sport Fury parts car. Love disc brakes!
    Mine IMG_20200201_141702028_HDR.jpg
     
  17. Mr onetwo

    Mr onetwo Well-Known Member

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    Take a look at the '73 specs...very confusing.They didn't use 2 different spindles.The guy got back to me on FB.He used Moog K7104 eccentric UCA bushings, but did not know what his alignment guy did to make it work. Here is an article from BigBlockMopar and an article from Allpar that may answer the questions Turn of the screw: front end alignment for performance on classic Mopars

    radial alignment.JPG
     
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  18. FK3 Sport Fury

    FK3 Sport Fury Hoser in a toque

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    I'm sure the Dakota parts would be more than adequate for a C body as the Dakota,being a truck,would be designed around it's max GVW which would very likely be higher than what a C body car would have been designed for...6 passengers and a trunk full of luggage.The larger wheel bearing and upper ball joint sizes would support that theory.
    If I was doing this to a car,I would be sure to check the camber as the suspension moves through it's travel.You can do this by removing the torsion bar and using a jack on the LCA to move the suspension through it's arc with either a piece of plywood that's straight upright or a camber adjustment bubble gauge to check for any major changes.
    Would also be good to run that test with the wheels steering in both directions in case the steering linkage causes some kind of issue.If the stock LBJ is used then it likely won't but it's good to check.
     
  19. savoy64

    savoy64 Member

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    looking at alignment specs probably not going to get you where you need to go-----i clamped the car and truck spindle to a jig and measured the offset to the center of the upper ball joint---that is where i saw a 5/8 inch difference---made a 5/8 spacer to go between the lower ball joint and lower control arm----before disassembly of original i made paint marks on the alignment marks on upper control arm---when i put the new stuff together i made the marks align-----car drove perfectly-----took it to alignment shop where they dialed it in---the tech said he had plenty of adjustment room no need for any offset bushings or offset balljoint....i have a loose dakota spindle but dont have a loose cbody car one to measure---maybe i will hit the old car yard to satisfy my curiosity....oh chrysler made spindles to inter change from the left to the right--on drum cars no problem--on disc cars--some models just put the calipers in front----the upper control arm is what adjusts to give you the castor...if the dakota spindle can be used without a spacer then that would be the way to go in my view....
     
    Last edited: Jul 22, 2020
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  20. Mr onetwo

    Mr onetwo Well-Known Member

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    I am kinda slow...could you make a sketch or post a photo of the jig? I can't visualize this.Thanks