Jeep JL Rear Highline Aluminum Fender Flares Install Guide

Highline Fender Flares · Install Video · JL Wrangler ·Dec 07, 2025

Upgrading to highline rear fender flares is one of the cleanest ways to gain tire clearance on a Jeep Wrangler JL without hacking the body or living with a flimsy, flexy flare. Our updated aluminum highline rear flares are built to take a hit on the trail, sit tight against the body, and play nicely with our corner armor and inner fenders.

In the video above, we walk through installing our latest rear highline aluminum fender flares on a JL – from rivnut locations and brackets, to spacer setup and final alignment. This article follows along with the video and highlights the key steps, tools, and tips you’ll want to know before you start drilling.

Why Go Highline on the Rear of a JL?

From the factory, the JL rear flares sit low and leave a lot of unused sheet metal over the tire. That can turn into:

Tire rub at full flex (especially on 37s and up)
More plastic to crack or rip off on the trail
Less usable uptravel for the same tire size

Our aluminum highline rear fender flares move the flare higher and tighter, creating more room for real suspension travel and bigger tires, with a solid, bolt-on mounting system behind it. Paired with our inner fenders and corner armor, you can build out a very stout rear corner that still looks clean.

What This Install Covers

This install focuses on:

Rear highline aluminum fender flares for the Jeep Wrangler JL
Updated bracket system with more support and better alignment
Using the spacer kit when you’re not running corner armor
How everything ties together if you are running our rear corner armor and rear inner fenders

We’ll use the driver side in the video, but the process is the same on the passenger side. All of our brackets are etched DS (driver side) or PA (passenger side) to keep things straightforward.

Required Hardware & Tools (Overview)

You’ll want to have the usual shop tools handy:

Rivnut / nutsert tool for 1/4-20 rivnuts
Drill and bits sized for 1/4-20 rivnuts
Allen/hex keys for button head hardware
Wrenches and sockets for nyloc nuts
Marker or paint pen to mark new hole locations
Safety glasses and basic PPE

The kit includes:

Rear mounting brackets (etched DS/PA)
Spacer(s) for installs without corner armor
Button head hardware, socket heads, washers, nyloc nuts, and 1/4-20 rivnuts

Step 1: Rivnut Locations on the JL Rear Quarter

With the factory rear flares off, you’ll start by confirming and installing the rivnuts that will hold your brackets.

Front section of the rear wheel opening:
- You’ll use three rivnuts: one low, one mid, one higher up on the vertical row.
- The top three holes along the very top of the opening stay open for this kit.
Rear section of the opening:
- Again, you’ll use three rivnuts in the vertical row toward the back of the wheel opening.

In total, you’ll have three rivnuts in the front and three in the rear per side, with the top row unused for this flare system.

Step 2: Rear Bracket Install

The rear bracket is the one with multiple holes toward the back.

Start with the bottom hole of the rear bracket into the lower rivnut.
Then fasten the next hole up into the second rivnut.
On the updated production bracket, there’s additional material that reaches up and grabs the third rivnut – that last button head with a washer will go through the upper portion of the bracket and into that third rivnut.

Get all three bolts started, then lightly snug them. We’ll do final alignment once all brackets are on.

Step 3: Center Bracket and Inner Fender Option

The center bracket has three holes and is the one that does a little more “work” depending on your setup:

The slotted middle hole gets a hex bolt installed from the top through the bracket.
That bolt passes through the middle hole in the body.

From there you have two paths:

If you’re NOT installing our inner fenders:
- Simply use a nyloc nut and washer on the back side to secure that hex bolt.
If you ARE installing our inner fenders:
- Now is the time to position the inner fender’s top mount from behind the body.
- The hex bolt passes through the bracket, the body, and that inner fender mount, and is secured with the provided nut and washer.

The other two holes in the center bracket use button heads and nyloc nuts with washers on the back side. Once they’re all in place, you can tighten the center bracket down.

Step 4: Forward Bracket on the Driver Side

The final main bracket on the driver side uses three holes in a row:

Each one gets a button head with washer into the rivnuts you installed earlier.
Once all three bolts are started, you can snug them down.

When tightening any of these brackets, there’s just a little bit of slop in the holes. Before the bolts are fully tight, push the bracket upward as you snug it. That slight upward bias helps the flare sit tighter and more evenly against the body later.

Step 5: Using the Spacer (No Corner Armor)

If you are installing these highline flares without corner armor, you’ll use the included spacer with two pressed-in PEM studs.

The spacer mounts directly behind the flare, using two specific holes in the flare.
Use the supplied 1/2-inch-long button heads through the flare into the pressed-in PEMs in the spacer.

A good trick here is to:

Start the top bolt first, then loosely start the lower one.
Leave the spacer slightly loose so you can move it up/down a bit once the flare is on the Jeep. This lets you fine-tune the alignment of the spacer relative to the body before you tighten everything for good.

If you’re running corner armor, the corner armor takes over this role and the spacer is not used in those same positions.

Step 6: Hanging the Highline Rear Fender Flare

With all three brackets tight and your spacer loosely in place (if applicable), you’re ready to hang the flare:

Prep all nine button heads and washers that secure the flare to the brackets.
Start with the middle top center hole in the flare. Get that one started first so it can hold the flare up for you.
Work your way around the flare, installing the remaining bolts into the brackets and the spacer.

At this stage, keep all the hardware loose. You want a little bit of wiggle room so you can:

Push the flare in toward the body
Shift it slightly up/down or front/rear as needed
Close up any gaps before everything gets tightened down

Once you’re happy with how the flare is sitting, push it firmly inward toward the body and tighten the bolts.

Step 7: Marking and Drilling for Corner Armor / Upper Rivnuts

If you already have our rear corner armor installed, you should already have three upper holes drilled and rivnutted in the corner.

In that case, you’ll install the provided socket head hardware through the flare and into those existing rivnuts (or corner armor threaded inserts, depending on your setup).

If you don’t have corner armor yet and you’re adding rivnuts directly to the body:

With the flare mounted and aligned, mark the locations of:
- The three upper holes along the top of the flare
- The lower rear corner hole
Remove the flare.
Drill those marked locations and install the supplied 1/4-20 rivnuts.
Reinstall the flare and hardware, using the provided socket head bolts in those new locations.

Once those are in and everything is tight, your driver side is complete. Repeat the process on the passenger side.

Fitment & Final Checks

Before calling it done, check:

Panel gaps: The flare should sit tight and even against the JL body. If a corner is floating, loosen that area, push the flare in, and retighten.
Tire clearance at full stuff: With the Jeep articulated or at least on a ramp, confirm the tire clears the flare and inner structure as expected.
Hardware: Make a quick pass to ensure all bolts are snug and any nyloc nuts are fully seated.

This is one of those installs where spending a few extra minutes on alignment pays off every time you walk past the Jeep or drop into a rock garden.

Ready to Upgrade Your JL Rear Flares?

If you’re ready to ditch the factory plastic and move to a highline, aluminum setup that’s built to be used, you can find our JL rear highline fender flares, matching rear inner fenders, and rear corner armor on our site.

When you’re ready to install:

Watch the full install video embedded above
Keep this article handy as a step-by-step reference
Reach out to us if you hit anything weird on a particular trim or setup

We design these parts the way we want them on our own Jeeps – tight fit, strong brackets, and enough clearance to actually use the suspension travel you paid for.