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Discussion Starter · #1 ·
Last night I finally installed the Mopar Rock Rails (p/n 82213525AD) on my '18 Trailhawk- took about six weeks to get them after ordering them from my dealer. After watching several videos and reading several threads on the installation process, it seemed that cleaning out the lower body filler foam, fishing the 12 upper sill mounting bolts per side up through tiny oval holes and then holding on to them while trying to push on the clip washer to hold them in place was the most difficult and time consuming part of the install. Some older kits apparently included a tool consisting of a moldable metal strap to hold the bolt and do this fishing, but mine didn't.

My thought after looking at the parts and my Jeep was why not just use rivnuts/nutserts placed into the holes where the upper bolts would be fished, and then just bolt the rock rails on? Turns out that re-engineering of that step of the process worked great! I started by drilling out the 12 upper mounting slots slightly right in the middle of each using a 12mm stepped bit. Drilling and setting the nutserts took about 15 minutes per side with a pneumatic nutsert gun- way faster than fishing those 12 bolts. I used large flange M8 stainless nutserts (which have about the same clamping area behind the sill sheet metal as the bolts) and then used the included bolts from the kit to attach the rail to the sill. All the other mounting points worked perfectly following the instructions.

Using this method, I was able to easily install both rails by myself in about four hours. The nutserts do result in a very slightly larger gap between the rail and upper body sill, probably about 2mm or so, but not much more than you'd get using the push washers to hold the bolts on from the backside. This additional standoff also ensures that no part of the rock rail rubs on the body. I also like that using the bolts from the outside-in looks much cleaner than seeing the backside of a nut/bolt combo.

If you're looking to install the Mopar Rock Rails, this adaptation can certainly make the install faster and easier while not losing strength.
 

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Great idea. Several of the aftermarket steps and rails use nutserts/rivnuts to attach. Looks like you used good quality parts and did a good job installing them.
 

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Discussion Starter · #7 ·
Do the rock rails hang down far enough to protect the fuel Evap and other tubes that run along the bottom of the frame rail?
In my '18 Trailhawk I didn't recall seeing any tubes running along or near the pinch weld seam front to back- they're all up under the center of the body. The only thing on mine in the area of the rails is the wiring harness that's in a plastic conduit on the passenger side, inside of the pinch weld- you can see it in the pic below. On my rig, the rails extend about 3/4" below the pinch weld.
 

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Hey your solution looks good but be aware the functionality and strength is not any where near as good as the OEM install method with bolts running out from the slots that are then tightened with nuts outside of the rail.

If you want your rockrails to be functional and strong to support the entire weight of your Jeep while offroading you missed it......

If you just like the look with some additional rocker panel protection you'll be fine. Why didn't you order the '18 Trailhawk w/rockrails installed at the factory? Would have been cheaper and stronger.
 

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Discussion Starter · #9 ·
Hey your solution looks good but be aware the functionality and strength is not any where near as good as the OEM install method with bolts running out from the slots that are then tightened with nuts outside of the rail.

If you want your rockrails to be functional and strong to support the entire weight of your Jeep while offroading you missed it......

If you just like the look with some additional rocker panel protection you'll be fine. Why didn't you order the '18 Trailhawk w/rockrails installed at the factory? Would have been cheaper and stronger.
Sorry, but I'll have to respectfully disagree with you. Swapping nutserts for nuts has no impact on this setup's strength. The nutserts have about the same clamping area behind the sill as the bolt head does, and the bolts can be and are torqued to the same OEM spec as the nut/bolt combo (17 ft/lbs). There is no difference in the vertical compression strength of this set up as opposed to a nut/bolt combo, as the nut is not what takes the upward impact forces imparted by the rail- the lower sheet sill sheet metal does via the bolt going through it. As installed, the rails have supported the full weight of the vehicle on jackstands without moving a millimeter- I'm not too worried about them standing up to an impact. And these 12 bolts aren't the only mounting points- there are a total of 25 per side- 10 additional bolts that go through the lower pinch weld, and three large flag bolts that attach from the bottom.

As for ordering them at the factory- I didn't want to wait two months. When I was shopping in February, none with the factory rails were on any dealer lot here in Denver. The exact rig I wanted without them was on the lot and the dealer got me a fantastic deal on the Jeep and the rails for $260 less than what they would have cost from the factory.
 

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Sorry, but I'll have to respectfully disagree with you. Swapping nutserts for nuts has no impact on this setup's strength. The nutserts have about the same clamping area behind the sill as the bolt head does, Not anywhere near as strong as a nut/bolt combo! and the bolts can be and are torqued to the same OEM spec as the nut/bolt combo (17 ft/lbs). There is no difference in the vertical compression strength of this set up as opposed to a nut/bolt combo, What about the horizontal compression strength? as the nut is not what takes the upward impact forces imparted by the rail- the lower sheet sill sheet metal does via the bolt going through it. As installed, the rails have supported the full weight of the vehicle on jackstands without moving a millimeter- I'm not too worried about them standing up to an impact. And these 12 bolts aren't the only mounting points- there are a total of 25 per side- 10 additional bolts that go through the lower pinch weld, and three large flag bolts that attach from the bottom.

As for ordering them at the factory- I didn't want to wait two months. When I was shopping in February, none with the factory rails were on any dealer lot here in Denver. The exact rig I wanted without them was on the lot and the dealer got me a fantastic deal on the Jeep and the rails for $260 less than what they would have cost from the factory.
Sorry have to disagree, Nutserts are never as strong as a nut bolt combo in the same thread size. What about horizontal forces acting on those rails and the lack of any metal in those slots holding those nutserts in place in the horizontal plane?? A nut/bolt combo has significantly more clamping strength to stay in place in those slots than a nutsert install would.

Nutserts are designed to expand outward to grip the panel they are placed thru.
Your install only catches the slots they mount into on the top and bottom (vertical plane) not all the way around as they were designed too for maximum strength.

They may hold for awhile but after several stress/load cycles they could loosen up, severely diminishing the strength of each fastener installed! Because your install only catches the slots on the top and bottom or vertical plane, but not on the horizontal plane, the initial install isn't a strong as it should be to begin with! And it certainly isn't as strong as the superior clamping force of the Mopar spec'd nut/bolt combo the engineers who designed those rails spec'd to support the weight of your 5000lb Jeep.

Like I said not the best install method for maximum strength for HD off-roading, but for looks and extra rocker panel protection they'll work fine. Your install saved time and aggravation, but lost strength in the process.

Looking at your signature with your other mods it appears you intend to do some serious off-roading not mall crawling??

Either way it's your Jeep... if your happy, I'm happy for you.
 

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Yes the consensus is nutserts do not provide as strong a connection as bolts of similar size and shape. They were invented to save time while assembly, but need to be properly sized for the job and most importantly, properly installed. They can easily be improperly installed with weaker results. There are tons of examples around. One can also forget to tighten bolts :)

That being said, rivnuts are widely used in high strength applications. The OEM WK2 roof rails are attached with nutserts. Tons of well made and regarded aftermarket side steps and rails install and work well with rivenuts. These also usually have re-inforcement plates to spread the load across a wider area and clear the nutsert head so the steps won't rock back and forth. For example, the AMP steps mount with mostly rivnuts (6-8 total per side). Bolts can have big washers, but if the metal is thin, without washers and reinforcement plates, i.e. improperly installed they can also easily fail.

So rivnuts work well where the metal and plates are thick/strong enough and properly installed. They are certainly adequate for a rail install. If the attachment area lacks strength, bolts are going to eventually fail too. For the strongest rails, it seems like they must be bolted to the truck frame... but the WK2 has no such frame. So the designers are more careful about locating mounting points and method.

Given that there are tons of rivnuts and bolts, the strength of this install should not be an issue, although potting into slots instead of round holes may hif one pause. Personally I found outfits on the cheap provide bolts and let the DIY suffer with the install, where higher quality products provide alternatives that may be more expensive but are easier to install in those hard to reach areas. I wonder if Jeep just cheaped out on these rails. Its certainly easier for engineers to think about bolts than rivnuts... and in a pinch they are probably not going to give much thought to the easiest way to install these with similar strength.
 
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