Detours Off-road Hardware

XJ / MJ Backbone Bumper System Installation

  1. Remove bumper/check for any damage in need of repair.


  2. Clean up exposed area, remove what you feel you no longer need in exposed area, note that 'nothing' needs to be removed to install your BackBone Bumper System, everything can remain stock if you like.


  3. After removing your steering box bolts, slip the BackBone up into position, align & install steering box bolts loosely, install all other bolts loosely as well, front 4 bolts should be installed with bumper skin brackets as shown.

  4. IMPORTANT CHANGE for units purchased after 3/15/08
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  5. Push the BackBone up close to, but not tight to the grill area, snug up all bolts *except* the bolts retaining the clips which will accept your stock bumper skin, allow those to move for now.


  6. If your fabricating your own bumper using the BackBone as a starting point, tighten ALL bolts, your install is complete. Disregard clips provided for the bumper skin.


  7. With *END CAPS OFF*, lay your stock bumper skin on a flat surface and layout/transfer your measurements as shown for best results. **All Measurements Are From The Ends of Bumper With CAPS REMOVED**
    1. All XJ front bumper skins measure 56.5" across the top.
    2. From both ends, measure in 16" (top & bottom of bumper skin)
    3. Transfer a straight line from the back of the bumper to Bend C on the top area, out line with tape, connect those 2 lines across Bend C, this is the area your removing on the top of the bumper, it should measure aprox. 24.25"-24.5". (refer to pictures provided, double check all measurements before cutting!)
    4. 1996 and prior bumpers, there's a small bend at the top of the bumper on the back side, measure AWAY from center section removed 5" and remove only the portion described so it will slide over the BackBone. (don't cut into the factory mounting hole, you'll be using that hole to mount) ***If you don't understand this direction, don't cut the section just described, you'll catch on when you attempt to install, it will be obvious at that point***
    5. Bottom of bumper skin, from your 16" measurement, measure inward 1" on both the left & right side, with tape, transfer these measurements up to Bend D, remove material between this area up to and across Bend D as straight as possible. This area will allow your recovery points to pass thru the bumper skin, refer to pictures for reference if required.
    6. Test fit your bumper skin, its better to remove less material than too much, you can always trim more material away as required.


  8. Use tape to reference your cuts, cut as straight as possible.


  9. There are many methods of cutting:
    • Plasma
    • Angle Grinder with an 0.45 wheel
    • Sawz-All
    • Dremel
    • (HINT)--All cutting required is straight cutting, an Angle Grinder works great, but a Plasma cutting makes the job super quick!


  10. Please practice safety, take your time while cutting!


  11. Test fit your bumper skin after cutting, trim/grind and smooth as required.


  12. Clean up & install the bumper skin to brackets provided, adjust brackets for best fit & tighten.


  13. When complete, you should have a clean looking system. After all brackets are in place and fit is satisfactory, remove bumper skin and install your winch. Tighten all winch bolts and reinstall bumper skin.

With bumper skin in place, the 2 rear bolts holding your winch down are no longer accessible and concealed from would-be thieves, your install is complete but please be sure to double check all your bolt connections.

***Need a bumper skin? They're available at jcwtruck.com for as little as $39.95, part number AJT492541 (84-96) part # AJT269735 (97-01)***