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Narrowing 9" ford rear on 1 side

Discussion in 'The Hokey Ass Message Board' started by No Plan, Apr 11, 2013.

  1. No Plan
    Joined: Nov 2, 2008
    Posts: 254

    No Plan
    Member

    I've got a ?, I'm in the process of narrowing a 57 Ford 9" rear housing on the long side(that's putting in 2 short side axles thus moving the pinion off center 2") I was talking to a friend about it & he claims if you offset the pinion it will toss the driveshaft...I think it doesn't matter.....I did a search & couldn't find any info about the results...Who is correct, I have all the pieces & I'm ready to cut now!!Need a ACCURATE answer a.s.a.p.
     
  2. black 62
    Joined: Jul 12, 2012
    Posts: 1,895

    black 62
    Member
    from arkansas

    no problem...
     
  3. Scott
    Joined: Dec 23, 2004
    Posts: 2,764

    Scott
    Member

    ditto
     
  4. MANY car come with the driveshaft offset to one side, Early Bronco's are a perfect example. Your friend knows not of what he speaks
     

  5. dreracecar
    Joined: Aug 27, 2009
    Posts: 3,476

    dreracecar
    Member
    from so-cal

    Driveshaft down angle just sideways
     
  6. chop32
    Joined: Oct 13, 2002
    Posts: 1,077

    chop32
    Member

    Ive run a similar setup in my '55 Chevy for years. As long as the pinion centerline and crankshaft/transmission centerlines are parallel (looking down from the top) you'll be fine.
    My '57 rear was of the small bearing variety, so rather than hunting for another short side '57 axle I was able to use a 28 spline 8" axle that was 3" shorter than the long side axle.
    An added bonus was that the 8" axle was much beefier than the original tapered '57 axle.
     
  7. nobby
    Joined: Jan 8, 2006
    Posts: 1,206

    nobby
    Member

    Hello , listen to your friend
    the long axle if you have a centred pinion axle 'even stock they come centred case off-set pinion'
    but if you have a centred pinion axle, the difference in the long and short is 4 and 1/8 inches
    if you fit 2 shafts the same length, your pinion will be offset 4 1/8 inch, also your case will be offset 2 and a bit inches and will look mighty stupid, as you will have the long and short tubes on the wrong sides.

    so, looking down at your axle, imaging the longer side shorter 4.1/8 inches, it will look awful

    if you want the axle you have 8 . 1/4 inches shorter, use the short as the long and take 8.1/4 fromt the long one with a respline - centred pinion offset case2 aqnd a smidge right, looking backk from the top

    if you want it about 6'' narrower- as I can't remember exactly 'doing it at the moment though'
    use the short as the long and take 'about 6 from the long' - you will centre the case and offset the pinion to the left about 1 and 3/4'' looking on the top rear wards - easy to do as the axle tubes are the same lennght
    /\ what I mean by easy to do is, you know the long one is 4 and 1.8 longer, so you remove
    that from the tube, machine the tube from the bearing housing and re-fit, fit the short side in.
    then cut the other side the same amount, and measure what you need
     
    Last edited: Apr 11, 2013
  8. Marty Strode
    Joined: Apr 28, 2011
    Posts: 8,798

    Marty Strode
    Member

    If you shorten it to accept two short (equal length) '57 axles, the pinion will be offset 4.375".
     
  9. V8 Bob
    Joined: Feb 6, 2007
    Posts: 2,966

    V8 Bob
    ALLIANCE MEMBER


    If you're trying to center the 9" banjo, you will still have two different axle lengths. The actual pinion offset in a 9" is about 15/16".
    Most/all production vehicles with pinion offsets also have the engine/trans offset (normally to the passenger side) the same amount, so the only U-joint working angles to consider are vertical. But when the pinion is offset to the engine/trans, this compound horizontal angle has to be included with any vertical U-joint working angles.
     
  10. iarodder
    Joined: Dec 18, 2012
    Posts: 214

    iarodder
    Member

    It worked on my pro street I sold last year and I drove it for 5 yrs. like that? I had Quick Performance in Ames, Iowa build the housing and they didn't think it was a problem, He's been building rear ends for years?.....The only difference was I had Moser axles in it. But yes it works just fine.
     
  11. It will work and I have done it on a 57' rear. Your center section will be centered which doesn't matter. I have a 30' Chrysler coupe and the factory stock original rear looks like a modern day rear end and the center section is centered in the middle from the factory. Of course you will have to relocate the spring perch after cutting.I had a bunch of early Ford 9's laying around so I decided to shorten one to see how it would turn out. A friend of mine who has a speed shop had done several so I decide to do one for my pickup project. Didn't look out of place or funny at all after it was completed. If I'm not mistaken a think the late 50's Old's rears are centered in the middle also. I had a 58' Old's rear a while back and I'm sure the center section was in the middle of the rearend.
     
  12. Forgot to mention, yes the pinion will not be centered, you will have an angle on the drive shaft, the u-joints should compensate for that. The couple my friend built never had issues with knocking out u-joints or anything like that
     
  13. 51 Hemi J
    Joined: Sep 27, 2006
    Posts: 394

    51 Hemi J
    Member

    I know people how run Ultra4 4x4's at 100plus mph in the desert with offset pinion - it is not a problem.
     
  14. nobby
    Joined: Jan 8, 2006
    Posts: 1,206

    nobby
    Member

    yes , sorry I got my sums wrong I do it inmm 105mm longer , can't do that fraction imperial, but twice its 210mm = 8.3/4''

    what length are you after?

    oh. p.s. it kind of works with the 8.8 as there pinion/diff is different, i thiink its 3 inches rather than 4 and half of 3/4
     
  15. krylon32
    Joined: Jan 29, 2006
    Posts: 9,397

    krylon32
    ALLIANCE MEMBER
    from Nebraska
    1. Central Nebraska H.A.M.B.

    When I started building customer chassis back in the 70's none of the trick pre built smoothy rear housings were available but 57/59 rears were easy to come by. My standard deal was to shorten the right side about 2 inchs and use a 61/64 Ford left side axle. Did I have no idea how many over the years. Also used the 61/64 rear brakes. 2 inch pinion offset to the right is common as 95% of the rears we use today are housing centered.
     
    Last edited: Apr 11, 2013
  16. nobby
    Joined: Jan 8, 2006
    Posts: 1,206

    nobby
    Member

    have you done one with 98-04 grand cherokee bearing housings and resplined shafts?
    so yo ui get the 12 inch brakes?
     
  17. No Plan
    Joined: Nov 2, 2008
    Posts: 254

    No Plan
    Member

    Thanks for the replies, I think I'm going to do as originally planned, if it tosses the d.shaft I'll know we were wrong.....God knows I'm wrong alot!....thanks again!!
     
  18. Chaz
    Joined: Feb 24, 2004
    Posts: 5,016

    Chaz
    Member Emeritus

    4x4 trucks have had offset shafts forever.
     
  19. Deuce Roadster
    Joined: Sep 8, 2002
    Posts: 9,519

    Deuce Roadster
    Member Emeritus

    My 32 3W Ford has 57 Ford 9 inch rear with the same exact set up under it. :D

    [​IMG]

    Works great with no issues :)
     
  20. Hnstray
    Joined: Aug 23, 2009
    Posts: 12,355

    Hnstray
    ALLIANCE MEMBER
    from Quincy, IL

    As long as your have the centerlines of of the eng/trans and pinion shaft parallel, the angle is just and angle.......the u-joint doesn't know any diffference, so long as it doesn't exceed the u-joints maximum angular capacity

    For those naysayers, please explain how driveshaft angling down a bit differs from one that angles to the side a bit..........

    Ray
     
  21. dano1930
    Joined: Feb 10, 2013
    Posts: 58

    dano1930
    Member

    A 57 stock axle cant be resplined as far as im aware, but you can buy a new one in any spline, length etc
     
  22. BACAGrizz
    Joined: Aug 27, 2009
    Posts: 201

    BACAGrizz
    Member

    As long as the up/down angle matches on the transmission and the side angle offset matches there should be no problem. Example: Pinion up 2°, trans down 2° = good to go. Side to side offset should be trans snout parallel to center line, pinion parallel to center line = good to go. The U-joints should both be rotating around axes that are parallel and that will keep them happy.
     
  23. 665.0coupe
    Joined: Feb 12, 2009
    Posts: 9

    665.0coupe
    Member
    from Salina, KS

    You guys are way over thinking this.

    Fox body Mustangs use equal length axle shafts from the factory, that means the pinion can not be centered between the tires.

    I agree that the rear axle should be square in the car and perpendicular to the engine center line, but if its not, the drive shaft will not spit out. Go look at how the rear suspension works on a dirt modified or dirt late model. The dirt modified I work on has the axle out of square by an inch to start with. We run the right side wheel base one inch longer than the left side. When the car is "up on the bars" as they call it, the left rear tire moves down about 6-8 inches and forward about 6-8 inches. The right rear tire moves up and rearward about 4-6 inches. The pinion angle also changes because the one suspension link that controls pinion angle has a spring in it.

    The only time I have seen a drive shaft come out is because some one forgot to tighten the u-bolts.

    Luke
     
  24. Why would it not work side to side, if it works up and down??
     

  25. It does work just fine,
    Some just don't understand what they know
     

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