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How can I tell if I have a dually rear end

Discussion in '6.9L IH & 7.3L IDI Diesels' started by G. Mann, Oct 15, 2020.

  1. G. Mann

    G. Mann Full Access Member

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    If I'm following your post correctly, even if the inner dual wheel location pin is missing, there would be a hole in the Wheel Mount Surface between two studs where it should go..
    And, if it is a non dual rear end it would not have that feature... ?? Am I guessing right on that point?

    You guys are great. Thanks a bunch...
     
  2. G. Mann

    G. Mann Full Access Member

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    BTW... I may have found a Dana 70 dual wheel rear end complete.. .less wheels... It's only 150 miles away.... hahah... damn...
    Looks like I might have also found a leaf spring, Dana 60 dual wheel hub front end, which is only 100 miles away, in the other direction...

    Ahhh... the build plan starts to come together... hmmm.. oops,, going to need a transfer case behind the ZF 5 speed...

    I already have 5 trucks, this makes #6... should I check in to a mental rehab clinic for truck addiction? [why am I asking this group... ;))
     
  3. Randy Bush

    Randy Bush Full Access Member

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    Not 100% sure , but I do believe there is a difference in a dually and cab/ classic dual rear end width.
     
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  4. chillman88

    chillman88 Supporting Member Supporting Member

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    I believe that was mentioned earlier. If I read it right they said outside width is the same as a SRW axle but the leaf spring perches are in the wrong spot. Regardless, the cab and chassis rears have narrower spring spacing and won't bolt up to a regular pickup frame.
     
  5. u2slow

    u2slow bilge rat

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    Be sure its not for an E350 or you have to move the spring perches.( ~50" spacing)
     
  6. secondjohn

    secondjohn Registered User

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    Don't know about '86, but later trucks tell "line, series, body type" in VIN digits 5,6,7 - including SRW or DRW
     
  7. BR3

    BR3 Full Access Member

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    As well as (on the 70 that is) it has to be from a pretty rare truck. 81-85 pickup bed dually. Pretty uncommon where I am. I've never actually seen one, but far be it from me to say they didn't exist. I've seen several things I didn't think existed on our trucks factory haha.All 86-96 hd axles were 10.25's besides the f-super


    As others have said, so just further confirmation, I'm certain if the following

    Pickup dually wms to wms -72.5"
    Pickup single wms to wms-70"
    CandC dually wms to wms-69"

    I'm not certain, but believe I remember that the f-super is 72.5" wms to wms.
    The perch locations are definitely the same on the f-super. Though you've got 10 lug Dana 80 there.so the wheels wouldn't match.

    One way to tell for certain if all else fails is bolt on the wheels, and measure if they are wider outside to outside than the fronts. Factory the srw was slightly narrower than the front and dually would have a srw wheel stuck way out.
     
  8. u2slow

    u2slow bilge rat

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    Your widths are almost correct for 2ndgen dodge, not ford.


    F250/350 SRW: 65"
    F350 DRW: 72" (pickup)

    C&C is very close to SRW width but do not have one to measure and confirm.

    Spring spacing on the 10lug f-superduty is less than a pickup; that's why the diff doesn't swap over easy. It may be a touch wider overall than a f350 c&c, but not 72" wms-wms.
     
  9. BR3

    BR3 Full Access Member

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    While they may be close to dodge measurements as well, the srw 10.25 is definitely wider than 65" wms to wms, the dually wheel only needs about another .5" to actually bolt on to a srw axle and clear the leafs. I can probably measure again this evening to be sure, but I'm 99% certain of those numbers.

    I'm not certain on the f super, but it definitely has 3" leafs, and it's entire own setup for everything, and I believe the housing was wider as well so that it could be more stable than the regular 34" frame c and c. Definitely not sure on that one though. I've never measured those
     
  10. u2slow

    u2slow bilge rat

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    I have three ford 10.25" SRWs at 65" wms... '90, '93, and '94. I have also widened one to 67.5"ish. (Two long side shafts).


    Agreed the f-superduty uses 3" wide leafs instead of the 2.25" on the F350 c&c. I believe it's diff is just extra-wide-enough to make that work on its 34" frame.
     
  11. BR3

    BR3 Full Access Member

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    I'll never be one to deny the truth, upon a new measurement of a couple of the 10 obs axles I have at the house, 65" looked correct for the srw, disregard my earlier post.
     
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