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Spartan Locker Install Ford 8.8 IRS

Discussion in '2007 - 2010 Explorer Sport Trac' started by Paul Fithian, May 15, 2019.

^^Searches ExplorerForum.com^^
  1. Paul Fithian

    Paul Fithian Elite Explorer

    October 12, 2016
    Likes Received:
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    City, State:
    Long Beach, IN
    Year, Model & Trim Level:
    2007 Job 1 RWD V8 Limited
    I completed installation of a Spartan Locker SLF8831 in the 8.8 IRS differential on my 2007 Sport Trac. Drives great with better traction!

    Although the Spartan catalog lists this unit for 2001-2010 Sport Tracs, it does not fit the 2007-2010 IRS version without modification. The axles cannot be pushed in far enough, they contact the carrier pin before the axle circlip can expand into the area inside of the side coupler.

    In order for the axles to clip into the side couplers, a 0.100" relief must be made for the axle circlip to expand into. See attached PDF on how to do this to an existing locker. I had correspondence with Gus at Randy's Worldwide, he advised that their engineering department will implement this change on future products. Note this change enables use of a Spartan Locker in post 2001 Explorers and Mountaineers with 8.8 IRS differentials.

    Part of this job was to replace the axle and pinion seals. The pinion seal was leaking due to driveshaft movement caused by a failed center bearing (7A2Z-4A499-A Bracket), which was replaced as part of this work.

    I had to fab up some tools to install the pinion and axle seals as well as the Front Insulators 7L2Z-4B431-A (bushing). Seals installed were:

    Pinion: SKF 18136
    Driver Axle: SKF18005 (new style, made in Taiwan by KOK)
    Passenger Axle: NAPA 27SS2850 (new style, made in Taiwan by NAK)
    Spartan Locker Ford 8-8 IRS Pin Interference1.jpg Spartan Locker Ford 8-8 IRS Pin Interference2.jpg Axle Seal Compare1.jpg
    Ford 8-8 IRS Insulator Install.jpg Ford 8-8 IRS Seal and Insulator Install Tools.jpg

    Attached Files:

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