To ensure the vehicle performs safely and as designed, we recommend replacing shocks & struts in pairs. If the damping rates are significantly different from side to side (like using different brand parts or mixing old with new) the vehicle body and wheel movement variations could cause handling irregularities. We also recommend performing an alignment after replacement. This will ensure proper tracking and protect your vehicle's tires from premature wear.

Lifetime Warranty

This item is backed by a Limited Lifetime Warranty. In the event this item should fail due to manufacturing defects during intended use, we will exchange the part free of charge (excludes shipping charges) for the original purchaser. Please keep your invoice for proof of this warranty.

  1. step : Removing the Wheel (0:40)
    • Pry off the center cap with a flat blade screwdriver
    • Loosen the lug nuts with the vehicle on the ground
    • Raise the vehicle with a floor jack
    • Secure the vehicle on jack stands
    • Remove the lug nuts
    • Pull off the wheel
  2. step : Disconnecting the Strut (1:06)
    • Apply rust penetrant to the strut mount nuts
    • Pry out the inner fender clips with a flat blade screwdriver
    • Pull off the inner fender
    • Remove the three 13mm nuts from the strut mount
    • Remove the 21mm bolt from the bottom of the strut
  3. step : Removing the Sway Bar Link (3:35)
    • Apply rust penetrant to the sway bar link
    • Turn the sway bar link with a 16mm socket and ratchet
    • Remove the 15mm nut from the top of the sway bar link
    • Hold the sway bar link sleeve with vise grip pliers
    • Loosen the sway bar link from the bottom with a 16mm socket and ratchet
    • Push out the sway bar link with a hammer and punch
  4. step : Removing the Strut (5:29)
    • Apply rust penetrant to the lower strut nut
    • Hold the strut bolt with an 18mm wrench
    • Remove the 21mm nut from the wheel knuckle
    • Loosen the two 21mm nuts that hold the control arm to the frame
    • Lift the wheel knuckle up
    • Pull the strut down and out
  5. step : Installing the Strut (6:41)
    • Lift the strut into place
    • Start the three 13mm nuts onto the strut mount
    • Turn the bottom of the strut to line up the bolt hole with the control arm
    • Push the 21mm bolt into the bottom of the strut
    • Push the 18mm bolt into the wheel knuckle
    • Fasten the nut onto the strut bolt
    • Tighten the strut bolt and nut
    • Fasten the nut onto the wheel knuckle bolt
    • Tighten the wheel knuckle bolt and nut
    • Tighten the three 13mm nuts on the strut mount to 20-25 foot-pounds of torque
  6. step : Installing the Sway Bar Link (8:44)
    • Put a washer on the sway bar link
    • Put a bushing on the sway bar link
    • Slide the sway bar link through the control arm
    • Put a bushing on the sway bar link
    • Put a washer on the sway bar link
    • Put the sleeve onto the sway bar link
    • Put a washer on the sway bar link
    • Put a bushing on the sway bar link
    • Slide the sway bar link through the sway bar
    • Put a bushing on the sway bar link
    • Put a washer on the sway bar link
    • Fasten the 15mm nut onto the sway bar link
  7. step : Tightening the Suspension Parts (9:30)
    • Support the suspension at ride height with a jack
    • Tighten the sway bar link nut to compress the bushings
    • Tighten the two bolts that hold the control arm to the frame to 110 foot-pounds
    • Tighten the wheel knuckle bolt to 110 foot-pounds
    • Put the inner fender into place
    • Push the plastic clips into the inner fender
  8. step : Reattaching the Wheel (10:39)
    • Slide the wheel into place
    • Start the lug nuts by hand
    • Tighten the lug nuts preliminarily
    • Lower the vehicle to the ground
    • Tighten the lug nuts to 100 foot-pounds in a crossing or star pattern
    • Reattach the center cap

Tools needed for replacement:

    General Tools

  • Floor Jack
  • Jack Stands

  • Materials, Fluids, and Supplies

  • Rust Penetrant

  • Pliers, Cutters & misc Wrenches

  • Vise Grip Pliers
  • Wire Cutters

  • Ratchets & Related

  • A Piece of Pipe (for leverage)
  • Ratchet
  • Torque Wrench

  • Screwdrivers & Related

  • Flat Blade Screwdriver
  • Pry Bar

  • Sockets - Metric

  • 13mm Socket
  • 15mm Socket
  • 16mm Socket
  • 21mm Socket

  • Wrenches - Metric

  • 16mm Wrench
  • 18mm Wrench

5.0 / 5.0
1 Review
5 Stars
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Perfect fit for 2004 Explorer NBX
Nice looking strut looks to be solid. Been on for a week or so now and no issues.
October 30, 2017
Purchased
4 months ago
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How-to Video:

(11:37 min)

Tools List:

    General Tools

  • Floor Jack
  • Jack Stands

  • Materials, Fluids, and Supplies

  • Rust Penetrant

  • Pliers, Cutters & misc Wrenches

  • Vise Grip Pliers
  • Wire Cutters

  • Ratchets & Related

  • A Piece of Pipe (for leverage)
  • Ratchet
  • Torque Wrench

  • Screwdrivers & Related

  • Flat Blade Screwdriver
  • Pry Bar

  • Sockets - Metric

  • 13mm Socket
  • 15mm Socket
  • 16mm Socket
  • 21mm Socket

  • Wrenches - Metric

  • 16mm Wrench
  • 18mm Wrench



This part replaces:

  • Monroe 171322
  • Monroe 181322
  • KYB SR4051

Vehicle Fit

  • 2002-2003 Ford Explorer 4 Door Rear Shock & Spring Assembly Driver or Passenger Side
  • 2004-2005 Ford Explorer Rear Shock & Spring Assembly Driver or Passenger Side
  • 2002-2005 Mercury Mountaineer Rear Shock & Spring Assembly Driver or Passenger Side
Part #: 1ASTS00509

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Customer Feedback

"Thanks for the fast reliable service. Great price, and the headlights were as good as oem or better!!! Keep up the good work..."
- Dwuan M.
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