Rocker Panel Guards - used on the Rubicon Trail

2 Big Broncos 4x4 Technical White Papers

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Take this information for "face value" and use with your own discretion and wisdom.


Buy/Find The Materials

What I've used for each side of my Bronco's rocker panels is 3x2 .25 thick box steel. A length of 48inchs fits nicely up inside the space available in my 1986 Bronco. I purchased this from a steel supplier for $15 /side.

I know Rade found some 3x1.5 .125 thick box steel and welded a .5 steel plate (same length as box steel) to the bottom for correct depth and additional strength.

3x2x48 box steel beam - .25 wall

Clean The Body's Rocker Panel

Each vehicle will likely need some cleanup under the doors where the rock guards will be pressed in. In my case, I had existing dents from previous trials and this required some time to strength out. You need to have room for the 3x2x48 box steel to press up inside.

Cleanup the underside of the existing rocker panels

Fitting and Cutting

Using the full length possible - 48inchs in my case, you will want to loosen up the front fender retainer bolt making room to fit the rocker guard in place. Also, in the rear are seatbelt nuts which require cutting a 1.5inch hole in the rocker guard to fit it nicely in place. According to my truck and measurements, the center point for a 1.5inch hole was 7.25inchs from the back end of my box steel (note: my box steel is a full 48inchs in length).

From end to center point is 7.25inchs on my '86 Bronco The hole diameter fitting around the seatbelt nut is 1.5inch

The Pressed In Fit

It is time to fit the box steel in place. I used a floor jack, blocks of wood, and carefully placed the front end up, inside the rocker panel space available - a tight squeeze near the front fender.

Fitting up front near fender retainer bolt (removed)

The back fit easily up in place, around the seatbelt nut using my floor jack and blocks of wood to press it up.

Floor jack and blocks of wood work great here The rear fits in nice and tightly

Drill, Tap, and Bolt The Rocker Guard

Using three 1.25 inch, 7/16 coarse thread bolts to secure the rocker guard in place required a little drilling and thread tapping inside the door step. I used a 3/8 drill bit and tapped the holes for each bolt. Placed some lock-tite on the threads and tighted up each bolt.

Starting with the front bolt/hole Tapping the hole for my 7/16 bolt Doing the rear bolt/hole next - center last

Finished Product

Now with the three bolts in place and snugged up you can start on the other side! Oh Boy.... I used up nearly 3 hours from start to finish.

Rear bolt in place Still have some clearence for the door - good deal That is a nice job

The Finished Product Works!

On our trip to the Rubicon, many of us had installed the rocker panel guards as described above. They worked well and we certainly had plenty of rock to test them on!

Keith has them installed for Rubicon

On note on 1978-79 Broncos. Berne drove his 1979 Bronco on the same trails hitting the same rocks without having installed any of this additional steel. From what he says, there wasn't the damage we expected and explained this on the older models having more and stronger steel then the 1980-96 models. Thanks for showing us that older is stronger Berne!

Kurt Hartsig - 1986 XLT Bronco

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