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Convert PowrLok 19 spline to 30 spline (D44)

Discussion in 'Early CJ5 and CJ6 Tech' started by FinoCJ, Apr 10, 2014.

  1. Apr 10, 2014
    FinoCJ

    FinoCJ 1970 CJ5 Staff Member

    Bozeman, MT
    Joined:
    Jul 18, 2013
    Messages:
    5,593
    A member has classified posted for Dana 44 19-spline Powr Lok (and in general the 19 spline can be found).
    From previous threads it sounds as though its possible to convert 19 spline to 30 spline to use in a flanged D44. From Oldtime in recent previous post:
    A 19 spline Powr Lok can be readily be converted to become a 30 spline unit.
    This is accomplished be installation of 30 spline side gears and side gear cups.
    That said an original 30 spline Power Lok unit is slightly superior to a modified 19 spline unit because of its carrier O.D.
    (carrier bearing I.D.)

    1) Is this a plausible way to go... Or is finding the side gears not going to be easy or worth it? Guess that is also a comparison of cost and quality vs the Yukon Powr Loks. Any thoughts?

    2) This would be replacing a Trac Loc, not an open diff...would that cause any problems (assuming you get the entire carrier)? Any additional parts needed?

    FWIW - setting up diffs and traction devices is probably something I would need a shop to do, but that is the case and cost no matter what route I go.

    thanks
     
  2. Apr 10, 2014
    nickmil

    nickmil In mothballs.

    Happy Valley, OR
    Joined:
    Sep 23, 2002
    Messages:
    12,529
    It's as simple as OldTime said. Simply swap in the 30 spline sude gears and clutch Rings. The 19 spline case journals are a smaller diameter so you must use the 19 spline case side bearings (carrier bearings). I've converted dozens of them. Used 30 spline side gears can be hard to find in good useable condition. They are available new through the aftermarket but aren't cheap.
    The oem case is much better quality than most of the aftermarket cases out there though so that adds to the equation.
     
  3. Apr 10, 2014
    tarry99

    tarry99 Member

    Northern California
    Joined:
    Oct 29, 2012
    Messages:
    3,784

    I think the key word is "Slightly" from Oldtime!.....I have seen many converted to the scout 30 spline side gears and parts with really no noticeable difference............in either the flanged or the older two piece housing using aftermarket axles.
     
  4. Apr 10, 2014
    jpflat2a

    jpflat2a what's that noise?

    Hermosa, SD
    Joined:
    Jul 30, 2003
    Messages:
    8,513
    Since Jeep never offered/installed the 30 spline units, look to IH Scouts for possible donors.

    PS..the Scout guys are well aware of this.
     
  5. Apr 10, 2014
    oldtime

    oldtime oldtime

    St. Charles,...
    Joined:
    Aug 14, 2006
    Messages:
    3,466
    Used Dana Spicer 30 spline side gears sets are out there but can be VERY hard to locate.
    New Yukon side gears are likely expensive and more readily available.

    There should be no unusual problems when converting from Trac Loc over to Powr Lok
    Just make sure you get the correct Final Drive Ratio (FDR ) series for your intended application.

    Availability and condition of a particular unit reflect onto the price.
    The D44 series 4 (STD) Powr Lok with 19 spline side gears is certainly the most abundant of all the Powr Loks.
    D25 D27 and D30 Powr Loks will be more scarce.
    Series 3 (AUTO) are much less common than series 4 (STD).
    But the common demand typically requires a series 4 unit.
    I just can't hardly imajine an off road jeeper wanting higher than 3.54 FDR


    Let's see what I recall:
    D25 Powr Lok series 3 none
    D25 Powr Lok series 4 for use with 4.09 through 5.38 FDR
    D27 Powr Lok series 3 for use with 3.73 through 3.07? FDR
    D27 Powr Lok series 4 for use with 3.92 through 5.38 FDR
    D30 Powr Lok series 3 for use with 3.54 through 2.54 FDR
    D30 Powr Lok series 4 for use with 3.73 through 4.88 FDR
    D44 Powr Lok series 3 for use with 3.73 through 2.54 FDR
    D44 Powr Lok series 4 for use with 3.92 through 5.38 FDR
    The above FDR numbers may need be edited......

    Primarily I suggest locating an original 30 spline unit if possible.
    Secondly I would consider modifying a 19 spline unit over to 30 spline side gears and cups.
    Lastly I would consider a Yukon unit.
    That simply reflects my "Made in America" prejudice.

    The 30 spline version of the D44 Powr Lok for either series is relatively rare due to limited original applications.
    Here in the U.S. the 30 spline D44 unit came into use in the early 1960's.
    They were used in 4WD GM/Chevy front axles and also in both front and rear IH 4WD's.
    The very early D44 30 spline units may differ slightly to those after the mid 1960's.
    The very early units had a 3 piece side gear /cup assemblies.
    All later units use 2 piece side gear /cup assemblies.
    The side gear and cup parts are interchangeable as complete sets and do not do not affect the remainder of the Powr Lok assembly.

    GROUP 21-03
    52979-----------------D41 / D44 (10-19 spline) differential carrier cone-----25577
    52980-----------------D41 / D44 (all) differential carrier cup----------------25523
    805311----------------D44 (30 spline) differential carrier cone---------------25590
     
    Last edited: Apr 10, 2014
  6. Apr 11, 2014
    oldtime

    oldtime oldtime

    St. Charles,...
    Joined:
    Aug 14, 2006
    Messages:
    3,466
    If you do convert a D44 Powr Lok from 19 to 30 splines make sure you buy the correct side gears and cups.
    You cannot use the side gears from a standard open differential.
    Jeep never used 30 spline Powr Lok so there is no Jeep part number for those 30 spline side gears.

    The cheapest and best route is to locate an old Scout front/rear or GM front axle D44 with Powr Lok.
    Plan on $300 plus if you find a complete good unit.
     
  7. Apr 11, 2014
    Im a doughball

    Im a doughball Member

    Oregon City
    Joined:
    Jan 8, 2011
    Messages:
    207
    Dr Diff in MT or WY has pretty reasonable new 30 spline side gear kits. Think they were $175 of so. Talk to Cass.
     
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