1. Registration trouble? Please use the "Contact Us" link at the bottom right corner of the page and your issue will be resolved.
    Dismiss Notice

Power Lock Center Pins And FF Conversion

Discussion in 'Early CJ5 and CJ6 Tech' started by Norcal69, Apr 28, 2017.

  1. Apr 28, 2017
    Norcal69

    Norcal69 Out of the box thinker 2020 Sponsor 2019 Sponsor

    Northern California
    Joined:
    Sep 6, 2014
    Messages:
    1,301
    I am having some issues with a Full float conversion that I purchased from Herm. Over the weekend, I stripped the splines on my short side axle. It appears that the axle pushed the snap ring out of the back of my warn hub. This allowed the axle to work its way out and then strip 1/8" off the splines. I removed the hub, cleaned the splines up with a file. The power lock was disassembled and inspected, the side gears appear to be fine. Reassembled with a drive flange this time, it appears that the short side axle is 1/8" to 3/16" too short.

    About 6 months ago, I scored a set of ecj5 axles for $100 on craigslist. 27 with a powerlock and a offset 44 rear with powerlock and full float kit with locking hubs on it. I felt really stupid after spending nearly $1000 only 6 months earlier, and threw them in my parts stash. Yesterday I tore down the rear axle I found that both rear axles had snap rings on the outer ends. In addition to the snap rings, they had a couple shims on each side to keep the axle pushed further in.
    On top of that, the short side axle was 1/8" longer than the short side axle that I received from Herm.( just what I believe I need) The long axle was the exact same length as Herms.

    I now understand the reason for the snap ring on the outer end of the axle is to give the drive flange or hub something to push against to retain the axle in the two gears in each side for the powerlock. The additional shims allow you to fine tune the axle depth. My axle kit as received from Herm did not come with any snap rings or shims.

    I pulled the powerlock out of the craigslist axle and found that it still had the center pins installed.
    When I installed my full float conversion I removed the center pins from my powerlock. What is Herm's reason for removing the center pins? The craigslist axle still has the center pins and appears to have been working just fine.
     
  2. Apr 28, 2017
    oldtime

    oldtime oldtime

    St. Charles,...
    Joined:
    Aug 14, 2006
    Messages:
    2,707
    First Lets back up a little...
    The sole reason for installing the center block spacer to begin with.
    The center block spacer function is to separate and space tapered axle shafts apart.
    In that way the two tapered axle shafts can essentially push up against one another.
    This is only required so that taper axle shaft wheel bearings can be adjusted via shim packs.

    With that in mind you can understand why center bock spacers are not required for use with flanged type axle shafts.
    The flanged axle shaft wheel bearings require no shim pack adjustment.

    Similarly the full floating type axle shafts do not require shims for wheel bearing adjustment.
     
  3. Apr 28, 2017
    william_cj3b

    william_cj3b 3BOB driver 2019 Sponsor

    Milton, FL
    Joined:
    Nov 17, 2003
    Messages:
    415
    :watch:

    Can't help you any, but I'm hoping someone with the knowledge chimes in. I have a powerlok in waiting for my 44 and a FF is on my wishlist.
     
  4. Apr 28, 2017
    Focker

    Focker That's what I do, I know things and I fix stuff. Staff Member 2019 Sponsor

    Tri-Cities WA
    Joined:
    Aug 18, 2014
    Messages:
    6,336
    No Powerlok, but I have a FF and I never removed the center block when I swapped out the tapered axles for the FF axles. No issues, everything fit and functions correctly. When I first installed the FF things weren't right until I did the passenger side too.

    This sounds like my setup. I simply pulled out the tapered axles and slid the FF axles in...I didn't remove any shims.

    Edit: I didn't use any shims or snap rings.
     
    Last edited: May 7, 2017
  5. Apr 28, 2017
    Norcal69

    Norcal69 Out of the box thinker 2020 Sponsor 2019 Sponsor

    Northern California
    Joined:
    Sep 6, 2014
    Messages:
    1,301
    Thank you for the answer. I'm curious as to why Herm says that they must be removed? If you have plenty of spline engagement with the tapered shafts, shouldn't you have plenty with the floating shafts? Provided they have a snap ring on the outer end to keep them from walking out?
     
  6. Apr 28, 2017
    Norcal69

    Norcal69 Out of the box thinker 2020 Sponsor 2019 Sponsor

    Northern California
    Joined:
    Sep 6, 2014
    Messages:
    1,301
    The shims were on the craigslist ff axle. They were used in conjunction with a snap ring on the outer end of the axle to keep the axle from walking out of the splines in the center section. They were not pre loading, just spacing the axle to the proper depth.
     
  7. Apr 28, 2017
    oldtime

    oldtime oldtime

    St. Charles,...
    Joined:
    Aug 14, 2006
    Messages:
    2,707
    Yeah well I can't imagine why Herm would say that.
    It does not make any sense at all unless a center block spacer is required to keep his full float axle shafts from entering too far into the side gears.
     
  8. Apr 28, 2017
    Glenn

    Glenn Kinda grumpy old man Staff Member

    Apopka, Fl
    Joined:
    Sep 21, 2002
    Messages:
    9,371
    It would seem that something else is not quite right if that small amount allowed it to disengage.
     
  9. Apr 28, 2017
    Glenn

    Glenn Kinda grumpy old man Staff Member

    Apopka, Fl
    Joined:
    Sep 21, 2002
    Messages:
    9,371
    I can see it being required as you mention, but I read that he is saying it must be removed. Something isn't adding up here.
     
  10. Apr 28, 2017
    Alan Rogers

    Alan Rogers New Member

    Joined:
    Dec 6, 2015
    Messages:
    10
    I have terms axles. I pulled spacer and you do not use any shims. No clip on end of axle. I spoke to herm for advice. works great. I switch between hubs and drive plates. I break hubs when hard use or sand tires on. I also run v8 that is hard on it
     
    Last edited: Apr 28, 2017
  11. Apr 29, 2017
    oldtime

    oldtime oldtime

    St. Charles,...
    Joined:
    Aug 14, 2006
    Messages:
    2,707
    Ooops I got it backwords again.
    It's like a He said / She said kinda thing.
    I thought earlier you stated the spacer was NOT to be removed
    So if Herm claims that the center block spacer "MUST BE REMOVED" then that makes good sense to me.
    In my mind it should not be required and could certainly interfere depending on length of full float shafts.

    I say the spacer is only for tapered type shafts and no spacer for full floating or flanged type shafts.

    Technically full float type shafts can be either flanged or they can be splined at the outer ends.

    If the full float shafts are splined then they need "something" to control both inward and outward end float.
    This shaft design is ideal for those who want to flat tow with rear freewheeling hubs.

    If the full float shafts are flanged; then the flange itself controls all inward and outward end float.
    I feel the full float flanged shafts are the absolute strongest design.
     
  12. Apr 29, 2017
    Glenn

    Glenn Kinda grumpy old man Staff Member

    Apopka, Fl
    Joined:
    Sep 21, 2002
    Messages:
    9,371
    This is what bugs me. What is missing in the equation where some guys have no troubles that arise from the conversion, yet others such as Norcal 69 run into issues? 3/16" shorter should in no way cause total disengagement. Can the type of locking hub be the issue?
     
  13. Apr 29, 2017
    jpflat2a

    jpflat2a what's that noise?

    Riverside CA
    Joined:
    Jul 30, 2003
    Messages:
    7,896
    Beats me.
    I ran a Four Wheel Parts FF kit with powr lok for over 20 years.
    Never had any axle/drive flange/locking hub issues you see reported with Herms kit.
    Never used the snap rings.
    Simply remove the power lok spacer buttons used with tapered shafts as stated in the instructions.
    Gotta say it's his kit or a component problem thereof.
     
  14. Apr 29, 2017
    oldtime

    oldtime oldtime

    St. Charles,...
    Joined:
    Aug 14, 2006
    Messages:
    2,707
    3/16" of spline disengaging is wrong but it should not be a catastrophe.
    If outward shaft end float is not controlled; the inner shaft splines can partly disengage from the differential side gears.

    If inward shaft end float is not controlled; The outer shaft splines could partly to mostly disengage from the freewheeling hub splines.
    The aluminum freewheeling hub splines could easily shear away.

    So I agree with Glenn: the question certainly does arise how long are the splines inside of a particular freewheeling hub. ?
    And furthermore what inside the hub can be used to contain the thrust of axle shaft end float ?
    A snap ring or shaft collar must be used to position the shaft splines in relation to the hub splines.

    edit : Perhaps in Jims scenario the hub spline /axle spline lengths happen to coincide in order to control end float.
     
  15. Apr 30, 2017
    Norcal69

    Norcal69 Out of the box thinker 2020 Sponsor 2019 Sponsor

    Northern California
    Joined:
    Sep 6, 2014
    Messages:
    1,301
    We believe that we have found the problem. When comparing the drive flanges that I received from Herm to the new warn hubs that I installed last fall, it appears that the drive flanges retain the axle deeper into the housing. When I switched to hubs, I believe that the axle was able to walk out to the point that it was only catching about 1/8th inch of the inner splines on the power lock. This Is what stripped out the end of the short side axle. My long side axle shows some wear but should be serviceable once it is pushed in all the way. When I re assemble, I am going to use snap rings on the outer ends of both axles to control the amount that the axle can walk out. This will also give us a way to shim the axle for optimum spline engagement while still letting the axle float. I will be using the new 1/8th" longer short side axle from my craigslist score. I have not yet called Herm about my problem. I know that he has an axle warranty, but If I were to spend more money on axles, I would order custom from dutchman or moser.
     
  16. May 1, 2017
    Norcal69

    Norcal69 Out of the box thinker 2020 Sponsor 2019 Sponsor

    Northern California
    Joined:
    Sep 6, 2014
    Messages:
    1,301
    Here is what my short side axle looks like. I believe that I could actually re use this axle if I cut off the damaged 1/8th". I would then use an outer snap ring and shim the axle in off the drive flange. Of course I would loose 1/8th" spline engagement on the drive flange. I would only do this if I were needing something to hold me over while waiting for custom axles to arrive.
    Short side
    [​IMG]

    Long side spline wear My side gears still look good, they fit tight when slid slightly past the worn portion.

    [​IMG]
     
  17. May 1, 2017
    scott milliner

    scott milliner Master Fabricator

    Seattle Wa.
    Joined:
    Dec 17, 2002
    Messages:
    2,029
    I'm not following this. I have FF axles. My snap ring keeps the axle from coming out of the locking hub, not the carrier. How is this possible?
     
  18. May 1, 2017
    Norcal69

    Norcal69 Out of the box thinker 2020 Sponsor 2019 Sponsor

    Northern California
    Joined:
    Sep 6, 2014
    Messages:
    1,301
    This snap ring is at the base of the splines on the outer end of the axle. It keeps the axle from sliding out through the center of the hub or drive flange. Ill try to take a picture of it when I get it back to my shop.
     
  19. May 1, 2017
    jpflat2a

    jpflat2a what's that noise?

    Riverside CA
    Joined:
    Jul 30, 2003
    Messages:
    7,896
    Maybe that's the problem....the hub splines are cut too long to allow the axle to move to far.
    I never used a snap ring on the axle anywhere.
    I'd probably re-use the axle pictured.
    Maybe the snap ring cures the problem.

    Did Herm respond ?
     
  20. May 1, 2017
    oldtime

    oldtime oldtime

    St. Charles,...
    Joined:
    Aug 14, 2006
    Messages:
    2,707
    Yeah I see no problem running the short shaft with the ends chewed up a bit.
    Just make sure they stay fully engaged from now on.

    That's what I was thinking way back.
    They have excessively long splines and so they need "c" clips to keep them engaged.
    Best "C" clip locations could possibly depend on the hubs being used.
     

Share This Page

New Posts