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Installing an RPG Offroad Frame Support Kit

Posted in How To: Suspension Brakes on September 21, 2016
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We love two-fers, or as it’s now called, multitasking. Being able to get more than one benefit out of a single thing appeals to our sense of efficiency.

Case in point is the RPG Offroad Frame Support Kit with Integrated Air Bump Mount. Quite a mouthful, but fairly self-explanatory. RPG Offroad is known for their killer Raptors, but this particular kit also fits F150’s, and they’re known to have a problem with frame stiffness.

Assembled from fully Mig welded A36 Low Carbon Steel, the patented RPG unit is actually a multi-pronged attack on what is a problem for most trucks, the dreaded frame-flex. It not only makes high speed runs iffy and towing a bumper hitch-mounted trailer sometimes interesting, it doesn’t take too many big hits and a bowing of the frame rails will begin. And we’ve all seen the vids of someone getting a little too exuberant off a jump and nearly taco-ing their truck.

Which is where this piece comes in as it strengthens the frame beneath the bed and provides for a solid bump stop mount for the rear suspension at the same time. RPG says you can use the Frame Support Kit without utilizing the Air Bump Mount, what they call Stage 1, but why? A bump stop is a great way of protecting your rear suspension when all else fails. RPG refers to a Frame Support Kit with an air bump mounted to it as a Stage 2.

The lowly bump stop has undergone a reinvention that can only be called revolutionary. It still does the same job as always, it just does it with a lot more capability. Traditionally, they have been rubber donuts that were a last ditch effort of slowing the suspension down before it slammed into the frame.

But companies such as King Shocks have taken the idea and ran with it. Now, bump stops are essentially shock absorbers that use air pressure. And in the case of King, their Bump Stops are, as are all of their products, technological works of art.

Available in 2.0 and 2.5-inch diameters, the bodies are made from 1/8-inch Chromoly that are Cadmium plated and honed to incredible tolerances. The Schrader valve features a double sealed cover that mounts to the body and an indexing pin properly locates the bump stop so no pinching of the tube occurs.

With stroke lengths of 2 to 4-inches available, the pistons in King Bump Stops feature large, hard chromed 1-5/8-inch shafts that have a tensile strength of 75,000psi. and are micro-polished to a 6RA finish. All that produces a nearly indestructible shaft that is also designed for long seal life.

Sounds too good, right? It’s all true; but maybe the best part is that the kit can be mounted without the need of removing the bed. We were at RPG and they installed a RPG Offroad Frame Support Kit with Integrated Air Bump Mount and went all Stage 2 on us when they added 2.5 King Bump Stops to it. These are the 2-inch stroke units, and will be perfect for those loaded down runs down a rough trail.

As stated, there’s no need to remove the bed, and the kit essentially bolts on. But there are a few particulars to know, so watch as this F150 gets more of what it really needs to hit the trail, even if it’s going to hit back.

The RPG Offroad Frame Support kit With Integrated Air Bump Mount can be used as a frame stiffener only (Stage 1), but with the addition of the air bump stops, it becomes a Stage 2 system.
The patented RPG unit is assembled using A36 Low Carbon Steel and fully Mig welded then powder-coated for a lasting finish. The thickness of the steel used in the kit is three times the thickness of the Ford F150 or Raptor frame.
The addition of King Bump Stops put the level up to a Stage 2 designation. This unit is a 2.5 with a 2-inch stroke. It has a 1-5/8-inch hard-chromed shaft while the body is made from Cadmium plated, 1/8-inch Chromoly that is machined to exacting tolerances.
With the truck up on jacks, the Brillstein shock is removed.
This 2008 frame is rated 4 stars (09 and newer are 5), and the RPG Offroad Frame Support kit will increase rigidity in the area directly above the axle housing.
The stock rubber donut bump stop is removed.
Measurements are taken off of holes currently in the frame and marks are placed along the inside of the frame.
A pilot hole is drilled.
A 1.5-inch hole saw is used to open up a hole on the inner section of the frame.
The RPG Stage 1 main bracket is slid into place. Know that RPG has taken care to fit the bracket as tightly as possible, so it may take a few taps with a rubber mallet to get the bracket into place.
Using the stock bump stop mount, the bracket is affixed to the frame rail. With the bracket in place, the holes for the mounting hardware are drilled.
A cross member is fed through the space between the bed and frame rails. It’s not necessary to remove the bed in order to install the RPG kit.
Though tight, it is possible to install the upper mounting hardware. Know that RPG Offroad supplies Grade 8 hardware with the kit.
Using painter’s tape, the nut is taped to a wrench.
The wrench is used to feed the nut into the hole and into position inside the frame rail to attach the hardware.
The hardware is tightened to 250-lb.ft. of torque
Again, RPG supplied Grade 8 hardware to ensure that the bracket is strong enough for the demands that will be placed upon it.
RPG uses a copper based anti-sieze on the King Bumpstop
The King 2.5 Bump Stop is tightened into place. RPG calls for 150-lb.ft. of torque
When using the Stage 2 configuration (no Deaver springs) the stock block needs to be modified. Luckily, RPG supplies detailed instructions with every kit.
The strike plate fits between the modified block and the spring pad.
The finished product is impressive. With improved frame rigidity thanks to the RPG Frame Support Kit and suspension protection via King Bump Stops, this F150 is ready for its next step.


King Off-Road Racing Shocks
Garden Grove, CA 92843
RPG Off-Road

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