Installing an aftermarket rear long-arm suspension on a 4-door Jeep Wrangler JKU or JLU can create clearance problems along the frame rails. Many long-arm suspension systems relocate the rear lower control arm mounting brackets, placing them in the same area where conventional frame-mounted rock sliders attach. The Motobilt MB1258 Frame Mounted Rocker Guards are designed to address this interference while maintaining the frame-mounted rocker protection needed for rock crawling and demanding trail use.
Unlike body-mounted rocker guards that rely on sheet metal or body mounts, the MB1258 rock sliders weld directly to the Jeep frame. This creates a barrier between the rocker panels and trail obstacles, transferring impacts into the frame rather than the body.
The MB1258 kit includes a pair of welded rocker guard assemblies with the rearmost frame mounting connections intentionally left off. Loose mounting tubes, plates, and gussets are supplied so the installer can position and fabricate the rear mounting connections around many aftermarket long-arm suspension brackets. This allows builders to work around relocated suspension components without having to fabricate an entirely new set of rock sliders.
The main slider sections are constructed from 2" DOM steel tubing. The frame mounting plates, end caps, center bracing, and gussets are made from 3/16" steel plate, with laser-cut and CNC-formed components used throughout the assemblies.
Designed for 2007–2018 Jeep Wrangler JKU and 2018-current Jeep Wrangler JLU 4-door models, these rocker guards are intended for builders who need to account for suspension bracket placement during installation. The kit ships in bare steel and requires fitting, welding, and protective finishing. Step-by-step installation instructions are included to guide the fabrication process.
Important Information
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Fits 2007–2018 Jeep Wrangler JK Unlimited (JKU) 4-door
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Fits 2018-current Jeep Wrangler JL Unlimited (JLU) 4-door
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Designed for aftermarket rear long-arm suspension applications
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Sold as a pair, driver and passenger side
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Weld-on frame-mounted rocker protection
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Main rocker guard assemblies arrive welded, except for the customizable rear frame mounting connections
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Includes loose rear mounting tubes, plates, and gussets
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Rear mounting connections must be positioned, fitted, and welded during installation
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Allows rear frame mounts to be fabricated around many aftermarket long-arm suspension brackets
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Main slider tubing constructed from 2" DOM steel
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Frame mounting plates, end caps, center bracing, and gussets constructed from 3/16" steel
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Laser-cut and CNC-formed steel components
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Requires installation by a qualified welder or fabricator
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Ships bare steel and must be painted or coated before use
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For standard JKU applications without long-arm suspension interference, see MB1158-JKU
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For standard JLU applications without long-arm suspension interference, see MB1158
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Made in the USA
Product Specifications
Part Number: MB1258
Vehicle Fitment:
2007–2018 Jeep Wrangler JK Unlimited (JKU) 4-door
2018-current Jeep Wrangler JL Unlimited (JLU) 4-door
Suspension Application: Aftermarket rear long-arm suspensions
Main Slider Tubing: 2" DOM steel tubing
Frame Mount Material: 3/16" steel plate
End Caps and Center Bracing: 3/16" laser-cut and formed steel plate
Rear Mounting Components: Loose steel tubes, plates, and gussets for custom fitting and welding
Mounting Method: Weld-on frame mounts with installer-fabricated rear mounting connections
Finish: Bare steel
Quantity: Pair, driver and passenger side
Dimensions (H/W/D): 51" x 10" x 8"
Weight: 160 lbs
Manufactured: Made in the USA
Related Motobilt Products:
Installation Notes
The MB1258 requires welding and fabrication. The rocker guard assemblies are supplied with the rearmost frame mounting connections left off so the installer can position those connections around the rear lower control arm brackets used by the aftermarket long-arm suspension.
Test fit both rocker guards against the frame rails and identify the suspension bracket locations before cutting, positioning, or welding the loose rear mounting components. The supplied tubes, plates, and gussets allow the rear mounting connections to be adapted to the available space. Final mounting geometry will depend on the suspension configuration.
The kit ships in bare steel. Complete all fitting and welding before applying the final protective finish. If powder coating is used before final installation, coating must be removed from all weld areas, and those areas must be protected after welding.
Always disconnect the vehicle battery cables before welding. Installation should be completed by a qualified welder or fabricator familiar with frame-mounted components and suspension bracket clearance.
Step-by-step installation instructions are provided.
Installation Resources:
MB1258 Product Components and Shipping Information
MB1258 Assembly and Installation Instructions
Frequently Asked Questions
Why do I need different frame-mounted rock sliders for a Jeep JKU or JLU with a long-arm suspension?
Many aftermarket rear long-arm suspension systems relocate the rear lower control arm mounting brackets along the frame rails. These brackets can interfere with the rear mounting connections of conventional frame-mounted rock sliders. The MB1258 provides loose rear mounting components so the installer can fabricate those connections around the suspension brackets.
What is the difference between MB1258 and the standard Motobilt 4-door rock sliders?
The MB1158-JKU for the Jeep JKU and MB1158 for the Jeep JLU use standard frame mounting configurations. The MB1258 is designed for vehicles with aftermarket rear long-arm suspensions and includes customizable rear frame mounting connections. If your Jeep does not have suspension bracket interference, the standard rocker guards are the appropriate option.
Are the MB1258 rocker guards fully welded when they arrive?
The main rocker guard assemblies arrive welded, but the rearmost frame mounting connections are intentionally left off. The kit includes loose tubes, plates, and gussets that must be positioned and welded during installation to accommodate the vehicle's suspension brackets.
Will MB1258 fit every aftermarket JKU or JLU long-arm suspension?
The MB1258 is designed to accommodate many aftermarket rear long-arm suspension configurations, but mounting bracket locations vary between suspension manufacturers. The installer must verify available frame clearance and determine the appropriate position for the rear mounting connections before welding.
Do the MB1258 rock sliders require welding?
Yes. These are weld-on frame-mounted rocker guards that require fabrication of the rear mounting connections. The kit should be installed by a qualified welder or fabricator. The rock sliders ship in bare steel and require a protective finish after fabrication.
