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Full-floating rear axles

Discussion in '40- & 55-Series Tech' started by Vicm, Feb 25, 2007.

  1. Vicm

    Vicm

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    It seams a lot of guys want rear ff axles.
    You know you can make your own.
    Using a stock sf axles, you need 2 plates cut in a certain way and
    10- 16 holes drilled in them. You bolt them into the backing plate brackets on each side after you cut the ends of the axle housings to shorten them. Also you need to weld them into the housings. Then you can bolt all parts from a front disk brake axle into the rear; calipers, spnildes, hubs and everything.
    you can use stock ff axle shafts or make custom made ones to accept locking hubs. Also you can made the short axle shaft with longer splines to go with FZJ80
    locking Diff.
    I did an axle like that last Dec. It was no big deal. The things I see some guys do here welding and modifying . I think this will be easy to do for many people.
    If people are interested I can give more info, But I don't get to read this forum that often, so it is better to send me an email,
    vicmasoud@hotmail.com
    fff1].jpg
     
  2. ridgerunner

    ridgerunner

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    quick question: what did you do for an inner axle seal? Or was one used at all?
     
  3. Poser

    Poser Oh...Durka Durka Durka. s-Moderator Supporting Vendor

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    If you have pictures of doing this, please post them up.
     
  4. Odyseuss

    Odyseuss SILVER Star

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    Please post as much info as you can on this swap. I would like to see pictures of your plates and how they were cut and drilled. I have been thinking about several ways to do this for some time. With the interest in rear disc and FF swaps it may be easiest to post the info here than receiving a ton of separate e-mails. looks sweet:cheers:
     
  5. mr_manny

    mr_manny

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    I suspect this type of upgrade does not run an inner-axle seal...
     
  6. Vicm

    Vicm

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    3 way actully to make the axle shafts seals.
    1- Press the seals into the spindles. I had to make the shafts 30.5 mm at the part that goes into the spindle.
    2- Use stock ff seals. This way seal holders have to be welded into the housings.
    3-Also you can use any seal you can find as long as the outside diam of the seal
    is the same as the stock sf seal and the inner diam match with whatever thinkness axles you are using.
    I have taken some pics, but I am having a hard time getting them to upload.
    I give more info most likely through email.
     
  7. 79fj40moneypit

    79fj40moneypit

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  8. Vicm

    Vicm

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    Yes that is my link

    I had wrote about this conversion.
    The reason I didn't want to post that link here, is because I am still not really finshed covering all the work. Initially I was hoping to make few of these plates for poeple that want them. I made the design for the first plate and had the plate cut and drilled at a local machine
    shop. Then made the other plate and finished the work. I had to do alot of thinking, figuring and measuring to get evrything right. I would not mind giving instructions to anybody that can get them made. Having a machine shop make them is the best way to go. If you can find other people that want them then the cost of making these plates will be much less when they are made in quantity.You can read all the explaining I gave on that link, but I feel that it is not complete . I am trying to post some drawings of the plates, but I am still not able to convert them to a file that can be downloaded here. Also I am working with dutchman to get them to make the axle shafts. The shafts I use now are made by welding shafts together. I did that just to get everything finished and working. It is cheaper for me to see if any changes are needed.
    Everything is working good and once I get the Dutchman shafts and
    the fzj80 locking differential,these axles are going to be awesome.
    Anyway I can email someone the drawings and they can post them.
    I am still sure that this was an easy conversion. If I can do it anybody can do it.
     
  9. Vicm

    Vicm

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    Here is a pic of the adapter plate.
    The thickness is 1"
    The Big hole in the middle has 2 diameters, the smaller diameter is the same as the diameter of the hole in the backing plate.
    This hole is 1/2" deep
    Then the diameter gets larger, the larger diameter is the same as the diameter of the front hole of the nuckle.
    the 6 ressed holes should line up with the 6 holes in the backing plate.
    So you can use the bacing plate as a guide to drill the holes.
    Here you can get away with only drilling 2 holes.
    the other 8 holes should line up with 8 spindle holes. Use the spindle to drill them

    Bolt the plate to nuckle , then you can mark the 2 caliper holes and drill them
    Or take a spindle , backing plate, and a nuckle to a machine shop.
    give them these instructions and ask to make the plate to 1" thickness. They will have no trouble doing that.
    They can do both plates at the same time. But you have to remember one thing .The 2 plates are merrior images of eachother.I will give more details .
    adapterplate.jpg
     
  10. Odyseuss

    Odyseuss SILVER Star

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    Thanks for the info this looks like a sweet setup. It could be a DIY swap but if some one put this together as a kit with shafts and hardware it would probably be pretty easy to sell.
     
  11. Poser

    Poser Oh...Durka Durka Durka. s-Moderator Supporting Vendor

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    Not picking on you....




    Very doubtful that this could come in under a grand.

    If it was really something that would generate cash, or that the market needed, don’t you think that someone would have produced it already?


    Further,


    When the guys with 38” tires have lockouts explode on them, tear the lockout-mounting studs from the wheel bearing hub, or grenades an axle, can you imagine the bashing of the product that would occur?


    You will need Chromo rear axles at a minimum if you are going to run a locker and 35” or larger tires. No, really you will. The splines will twist off on a resplined stock axle.


    You are going to need a Chromo lockout drive gear, or your lockout drive gear will explode, ruining the axle shaft splines in the failure.

    You will need ARP hub studs to secure your lockout or drive flange, or you will be shearing those, just the same as the knuckle studs shear.







    If you are only running 33” tires, why do you need a full float axle?








    With all of this said, I am going to be doing a GM disc brake conversion on an early Land Cruiser 40 series full float axle for a friend. Along with the GM disc brake conversion, it will have CTM rear axle shafts, the Chromo lockout drive gear and the ARP hub studs installed. There will be a thread out here on it in the not too distant future. That is what he wants for his application, and it should work out very well for him.




    :beer:
     
  12. grant5127

    grant5127

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    Did the Philosophy of this thread just get shot down??.. someone needs to turn-on the exhaust fan to clear the smoke...
     
  13. D'Animal

    D'Animal Rescuer of Beagles & Landcruisers Moderator

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    Poser brings the reality to the party.



    Exhaust Fan Is Now On.
     
  14. Vicm

    Vicm

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    The reason I wanted this kind of rear axle is not to run big tires.
    Actually I won't run any tire bigger than 32" myself. I tow my truck regularly so
    the free wheeling makes it easier.
    For those who have no faith in the maual locks, why do they run them in the front.
    I said that the best axle shafts you should use on this type of FF rear should the stock FF axle or stronger.
    Let me say somthing about manual locks, the problem they have doesn't come from them,but from the axle shafts. The locks can be protected if the axle shafts are made not to move sideways. Just also remeber that your side gears lock to the axle shafts the same way as the manual locks do . THis not to say that a fixed lock is not better,like a dirve flange.
    Another full floater kit is sold by FROR for the Toy Trucks also uses the same locking hubs. But I don't like the way their axles are set up.
    Please read all that I had to say about this issue , don't just assume stuff and reapet things you hear without looking at things for yourself to find out what is
    logical and reasonable .
    .
    Another reason I went with this conversion is the fact that I don't believe in rear disk brakes on SF rear axles and even so when you are using different non TOY calipers.
    At the end I am not here trying to sell you something,but to share something with you, and If you show me a reasonable explaination that this type of setup is not worth the effort, I will be very greatfull to you.
    All comments that I get I take with good well and I it is better that we share them and look into them amy be we can learn and benefit from them.
    I will,however remaind you that don't form your opinion hastely, because if one thing I learned, that would be such people who do such a thing they hardly change their minds even when they are 100% wrong.
    Thank you.
     
  15. Odyseuss

    Odyseuss SILVER Star

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    Your right it would be expensive. I would expect chromo axles, drive flanges or chromo gears, studs, etc...

    Warn used to make a kit. I don't know why they don't anymore but I wasn't aware of any problems with it.

    Maybe it would be easier and cheaper to convert a FF to disc. I will keep a look out for your thread on it.
     
  16. mr_manny

    mr_manny

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    Vicm,
    I believe I read that you recently build this axle...Is it too soon to ask that you share your experiences?

    One question I have, is on those brake calipers:
    I'm running 4whl disk brakes (big vented frt/MC rear) and feel that this design would be more balanced if the rear caliper was smaller (no need to run a portioning valve).
    Have you experienced any brake balance issues w/those 4 piston rear calipers?

    Also, If you were to build another, would you do anything differently?

    I'm sure I'm not alone when I say "Thank you take the time to share your experiences on your FF build".

    manny
     
  17. Jetboy

    Jetboy

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    Thanks for the write up! It looks like this might be easier to make with two 1/2" plates instead of one 1" plate. This way it would only require cutting and drilling, but not any "milling" of recesses. Probably something I could make without much machine shop time. It just seems like it might be faster that way, and possibly cheaper to make. The plates could just be welded or even bolted together if done properly.

    I'd also like to hear back on how it holds up after some use.
    Thanks
    jetboy
     
  18. Poser

    Poser Oh...Durka Durka Durka. s-Moderator Supporting Vendor

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    Too expensive to manufacture and sales were not there to support it.
     
  19. Poser

    Poser Oh...Durka Durka Durka. s-Moderator Supporting Vendor

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    I talk from experience, I live this:



    Blown up Warn lockout, which destroyed the splines on the 35 spline 4340 rear axle shaft.


    [​IMG]



    Twisted off driver side front inner Dana 60.


    [​IMG]




    Read about it here if you wish. <---- this is a link




    This stuff is significantly stronger than stock Toyota axles, which I have also broken, with 33" tires, long before the days of IH8MUD or other internet lists and forums.





    When Long came out with the 30 spline Chromo front axle super sets, the next piece in the chain to fail was the stock internal drive gear in the Toyota lock out. Further, the ARP studs were introduced to replace the stock studs that were stretching, distorting and ultimately shearing under load, which is another issue that folks that run the Toyota disc brake front axle were experiencing. This is on the front axle, which rarely sees the same load that the rear axle in the same vehicle will experience.

    Now install those same lock outs on the rear axle of a truck and ask them to perform. It is not difficult to see why they will likely not live very long back there, and why the upgrades would be mandatory for anyone running a larger tire.

    If you do not ever see yourself going beyond a 33” tire, you may get by just fine.




    Don’t paint with to broad of a brush....you may get paint on yourself. :)




    :beer:
     
  20. Poser

    Poser Oh...Durka Durka Durka. s-Moderator Supporting Vendor

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    What was that again?