Will this set up be ok? CV drive shaft in the rear ok?

Discussion in '40- & 55-Series Tech' started by DAD2SIX, Feb 18, 2014.

  1. DAD2SIX

    DAD2SIX SILVER Star

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    Will this work ok??

    I just Put a 2f 4 speed and split case out of a 84 FJ60in my 65 FJ40

    I knew I was going to have to have my rear drive shaft shortened and my front lengthened.

    While measuring everything and getting ready to head over to the driveshaft shop I figured out that the slip yokes between the FJ60 donor and my FJ40 interchange. Giving me the correct ends to match up on both ends front and rear. Cool!

    Also noticed the front FJ60 shaft was the exact length I needed for the rear!

    So if I use it in the rear I would only have to have one shaft made for the front saving me a few hundred bucks!

    Is there any problem with using the front cv shaft in the rear?
    Anything I'm not thinking of?
    It all lines up bolts up. I think. Will be ok. What do yea say????

    The picture is of it sitting on the ground. Regular height.
    image-1708475311.jpg
  2. offcamberfj

    offcamberfj SILVER Star

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    I run the same thing in mine and it works fine. Ive got a lot more slip in mine though.
  3. DAD2SIX

    DAD2SIX SILVER Star

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    670
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    How much slip is recommended?
  4. John Smith

    John Smith In the garage GOLD Star

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    Enough so you don't bottom out, and crack the transfer case apart. Fully cycle your suspension to find out if you have enough slip. Looking at your picture, you may be cutting it a little close. Are your rear springs flipped?
  5. DAD2SIX

    DAD2SIX SILVER Star

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    No the springs are not flipped. I did drill another hole in the perch moving the axle back 1"
  6. Fast Eddy

    Fast Eddy SILVER Star

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    I agree that you should probably be showing more of the slip joint at ride height.

    As it sits it's out of phase too, but it matters much less with a CV joint.
  7. DAD2SIX

    DAD2SIX SILVER Star

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    670
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    I'm thinking about cutting about a 1" off of the splines and cutting off the spline cover and cutting 1" out then welding the cover back on.
    That should give me plenty of travel either way. No?
  8. bikersmurf

    bikersmurf

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    The old school hotroder who shortened recommended 1" of play... No problems 18 years later.

    CV would be fine. It's also easier/cheaper to shorten a shaft than lengthen one.
  9. Fast Eddy

    Fast Eddy SILVER Star

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    No. You need to remove an inch of tube if an inch is the amount. As mentioned above you need to cycle the suspension to know how much slip you need. With a short shaft you want as much as you can get, so shortening the splines is a bad idea.

    Drive shafts aren't cheap, but once they're right, they're done.
  10. bikersmurf

    bikersmurf

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    I'd drill the spring plates and move the axle back to allow 1" of yoke... Since I'm running 33s, cut wheel openings, etc... So long as it still cleared the auxiary fuel tank.
  11. DAD2SIX

    DAD2SIX SILVER Star

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    If I flip the rear springs I would move the rear axle back about 3" and if I drill the perch rearward of the stock hole I would move or forward 1" netting a 2" extension. I wonder if that would be ok?
    Last edited: Feb 18, 2014

  12. bikersmurf

    bikersmurf

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    Yes, the CV in the rear will work fine.

    You'll want 1" of play in the splines... 2" back would be too far (unless you've got an extra long slip joint).
    I'd keep the military wrap at the front of your spring pack and drill the spring perch and plate to move the axle back as needed ie. 1".
  13. Fast Eddy

    Fast Eddy SILVER Star

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    Seems about right. If you want to fix the fenders afterwards, take a look here:

    http://forum.ih8mud.com/40-55-serie...r-protection.html?highlight=fender protection

    I could do another run of these with as few as two orders.

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