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75 series knuckle and birfield

Discussion in '70-Series Tech' started by theyis, Mar 3, 2007.

  1. theyis

    theyis

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    Anybody have info or pictures of the 75 series knuckle and birfield? I have heard that it has the steering arms on top but uses the same size birfield as the 80 series. Can anyone confirm this for me? Pictures would be good too if you have them.

    Thanks
     
  2. rick_d

    rick_d

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    forward steer arm type 8" diff (so, 1990-1998) use birfields that are only slightly larger than 1979-1990. I tried several years ago to fit 80 series into a 1995 housing with no luck.

    30 spline Long Fields do the job even better than a 80 series factory idea.

    the rear bottom steer arms 1999 and later, coil front ends use the 80 series size birfields.


    hth
     
  3. theyis

    theyis

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    That was my other option. I am swapping 80 axles into a 40 so I wanted to keep all of the 80 stuff except the knuckle. I am trying to find a knuckle that will fit over the 80 birfield but has the steering arm on top instead of underneath. Any ideas?

    The other option I am toying with is taking the ball out of a 60 series housing and putting it into the 80 housing. That would allow me to run the 60 series knuckle. I'd need to run an 80 series inner axle with the 60 series birfield outer axle. Longfields of course. I need to do some research on that one though...
     
  4. rick_d

    rick_d

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    you want the 8" front diff?

    ...ok.

    I'd scrap the 80 front end. on a 40 series.

    option A
    Use 1968-1984 40 series OR 1984-1990 70 series (move front spring perch, axles are same width). Install 9.5" elocker or whatever w/ 30 spline longs

    option B
    for wider track, use J60/61/62 front axle but please note, the right side spring perch is an issue spring under.


    I'd re ask this question on the 40 section or hard core and get guys like Poser to chime in.

    the 9.5" is certainly stronger than the 8" reverse cut any day of the week (strong, multi year evidence from canadian mine truck use where ratio is 1:6 in favor of the 9.5"- rear.