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RWD axle widths and interchange

Discussion in 'Other classic cars' started by TWX, Sep 8, 2009.

  1. TWX

    TWX DO NOT FEED THE TROLLS!
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    Like the thread I've started for engine/transmission bellhousings, I'm looking to put together a list of dimensions of rear axle mountings for RWD cars. I currently have the following:

    Code:
    Body    Years    Width  Perches  
    
    A-body  65-72    55.6    43.0   4" lug bolt circle 
    
    B-body  62-70    59.2    44.0
    B-body  71-79    62.0    47.3
    B-body  71-79    63.4    47.3   station wagon
    
    C-body  64-72    63.4    47.3
    C-body  65-69    Conflicting data saying perches are same as E-body
    C-body  73-78    ????    ????
    
    D-body  64-72    63.4    47.3 Imperial?
    
    E-body  70-74    60.7    46.0
    
    F-body  76-80    ????    ????
    
    J-body  81-83    ????    ????
    
    M-body  77-89    ????    ????
    
    R-body  79-81    62.0    47.3
    
    I'd also like to do this for trucks and vans.
     
  2. dana44

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    OOO OOO OOO, not to make things easier or harder, but this information may be found over at the Mopar Muscle website. I recall back over the years I have been getting the magazine (10-12years now), that they had this rear end width and perch locations once and there was even a K member application to engine size listing. These two things were within the past three years (yeah, here and there, Gitmo to Guam and Iraq, reading them in stacks at times, which issue doesn't really matter), so I can't give specifics, just the fact they were done.
     
  3. TWX

    TWX DO NOT FEED THE TROLLS!
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    I'll have to see what I can find of that. A friend of mine has lots and lots of Mopar-themed rags, so maybe he has those.
     
  4. valiant67

    valiant67 Rich Corinthian Leather
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    Though the mounting system changed, all 71+ B bodies (and the R bodies) had the same perch and axle widths, with a wider axle for the wagons when they were available.

    How is width measured in that table? Most times I have seen it listed as flange to flange, but those measurments are larger so it must be hub to hub or something else.

    F/J/M were 53.34" wide flange to flange, perches 44.46.
    This way, a B body (except SW) is 57.8" wide flange to flange with the same 47.3" perches.
     
  5. Bearhawke

    Bearhawke Things happen for a reason

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    The 1965 B body was a (good) mongrel: it used the 1962-64 width/mtg perches but had the 1966+ style flanged axles...........in fact; said one year only drum to drum was/is an excellent upgrade into the older cars to get away from those Godawful 'knockoff' rear brake drums.
     
  6. TWX

    TWX DO NOT FEED THE TROLLS!
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    I collected that data around the Internet. I'll have to find out more when I have a moment. Otherwise I'm at least going to update the B/R bodies to reflect the info.
     
  7. dana44

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    They also had a list of front disc brake swaps, which is another common request.
     
  8. Trailmaster

    Trailmaster Move Over Plymouth Aproaching Rapidly

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    I got the truck info squirreled away somewhere in my notes, will see if I can find it.
     
  9. valiant67

    valiant67 Rich Corinthian Leather
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    There's got to be a standard for the width to make them comparable.
    1) Measure inside from flange to flange. I think this is the most common, but not 100% sure, but it is the easiest to measure accurately.
    2) Measure outside from hub to hub. This works, but is harder to measure accurately with the drums on the axle.
    3) I've even seen them measured from end of the lug nuts across, this way would be the least accurate because studs could be aftermarket, esp. on a race axle.
     
  10. Trailmaster

    Trailmaster Move Over Plymouth Aproaching Rapidly

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    I'm thinking the measurements that are going to be needed are from wheel mounting to wheel mounting and center to center on the spring pads. Usually to get acurate measurements I measure from a fixed point that is the same on each drum and then add the distance from there to a straitedge set on the wheel mounting surface.
     
  11. superduckie5000

    superduckie5000 THE MAD DUCK
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    Hi; Here's a Link with Some More Sizes: http://www.440magnum...rrearaxle.shtml

    1963 - 1972
    7 1/4" A-Body 53.200" 43.02" 10.09"
    1973 - 1976
    7 1/4" A-Body 51.400" 43.02" 10.09"
    1973 - 1976
    8 1/4" A-Body 51.400" 43.02" 11.69"
    All
    8 1/4" B-Body 57.800" 47.30" 11.69"
    All
    8 1/4" C-Body 59.200" 47.30" 11.69"
    All
    8 1/4" F-Body 54.340" 44.46" 11.69"
    All
    8 3/4" A-Body 51.400" 43.00" 12.35"
    1962 - 1970
    8 3/4" B-Body 55.000" 44.00" 12.35"
    1971 -1974
    8 3/4" B-Body 57.800" 47.30" 12.35"
    All
    8 3/4" E-Body 56.500" 46.00" 12.35"
    1971 -1974
    8 3/4" B-Body S.W. 59.200" 47.30" 12.35"
    All
    9 1/4" B-Body 57.800" 47.30" 11.69"
    All
    9 1/4" C-Body 59.200" 47.30" 11.69"
    1966 - 1970
    9 1/4" B-Body 54.936" 44.00" 13.47"
    All
    9 1/4" E-Body 56.500" 46.30" 13.47"
    (1st Dim) = Flange to flange. (2nd Dim) = Leaf spring centerline to leaf spring centerline.. (3rd Dim) = Centerline of axle shaft to centerline of rear universal joint.
     
  12. opus65

    opus65 Member

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    How does the Dakota 8.25 stack up against the Fbody 8.25?
     
  13. valiant67

    valiant67 Rich Corinthian Leather
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    The Dakota is supposedly close from what I've read on another board, about 57.2" flange to flange, with 43" for the pads. The 2wd Dakota axle mounts the same as the cars, the 4wd does not.
    I've seen people use 8.8" Explorer axles as well so they must be close too.
     
  14. cardude59

    cardude59 New Member

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    i am working on a 1957 belvedere and have the keyway rear hubs. is there a solid flange axle shaft that will be a direct install to the 8 3/4 rear end that is in the car now?
    i am also wondering about rear drum brake backing plates and front disc brake parts from later model cars or trucks that can be installed on this car you know, steering knuckles etc... thanks in advance for any info i can get .
     
  15. dana44

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    Welcome to the forum. To the best of my knowledge, when the attachment setup was changed on the 8.75, nothing swaps. Kind of like trying to put a big block to a slant six transmission, just not possible. Hopefully someone else can verify this. It would probably be easiest to replace the whole rear end if you have a lot of missing parts or the need to upgrade, otherwise any rear end of the same spindle style should work.
     
  16. cardude59

    cardude59 New Member

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    thanks for that insight. anyone else with more info or ideas would be helpful.i was hoping i would not have to do a complete swap. the car now is all orignal and complete. it runs and drives great, i would like to keep as orignal as possible but the reliability and safety factors are a concern.
    i would still like some info for the front disc conversion. does any other front steering knuckles swap in to the belvidere for the conversion or am i stuck with after market jerry rig stuff?
     
  17. dana44

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    You should be able to do a search of different newer models to conduct the swap with other Mopars, others have done it. Several of the Mopar magazines have lists of parts and models to do the swap.
     
  18. rockosocko

    rockosocko Member

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    I found a SRT-10 truck rear (13" discs, 4.10 posi, OH, and it's a Dana 60!) Going to ask him what the widths measure out to be.
    BY the time I'd have to go find a '489' chunk, shorten mine or donor to MY wheel/tire spacing, respline, bearings/seals, IF NEED BE, move perches, paint,
    restore/upgrade brakes... Yadda yadda.
    It might be cheaper to get the Dana

    Errol
     

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