Welcome back to the build! If you’ve followed the series, you now have the lift (Part 1), the tires (Part 2), and the reinforced drivetrain (Part 3). You’ve invested time and serious money into lifting your Jeep’s critical components off the ground. But just raising them isn't enough; you must protect them.

This chapter is all about armor—the heavy-duty steel and aluminum components that absorb impact so your Jeep’s delicate mechanical guts don't. Think of this as cheap insurance against the high cost of trail recovery or, worse, a busted transmission pan miles from civilization.

Section 1: Rock Sliders—The Essential Body Shield

If you only buy one piece of armor, make it Rock Sliders. These run along the bottom edge of your Jeep's body, between the front and rear wheel openings.

Why They Matter and Slider Design

When traversing rough terrain, your Jeep’s center point (the belly) will inevitably encounter rocks or logs. Without sliders, that impact is absorbed by the sheet metal of your rocker panels (the bottom edge of the cab), which crumples instantly and can damage your doors. Sliders are robust tubes or plates designed to act as a sacrificial barrier, allowing your Jeep to slide over the obstacle.

• Frame-Mounted Sliders (The Only Way): These bolt or weld directly to the main chassis frame. They are the strongest option, designed to hold the entire weight of the Jeep—they are a certified lift point and can absorb massive vertical impacts without deforming the body.
• Body-Mounted Sliders (For Looks Only): These attach to the body mounts or pinch seam. They offer protection against light trail scrapes and parking lot door dings, but they are not designed to take the full weight of the vehicle dropping onto a boulder.

 The Down-to-Earth Takeaway: Spend the extra money for a quality frame-mounted slider. It’s the only way to guarantee that when you drop hard onto a rock, you’ll be sliding and not crunching.

The "Kick-Out" Feature

Look for sliders with a "kick-out" at the rear. This design pushes the slider out slightly near the rear wheel well. When your long wheelbase Jeep is maneuvering a tight turn around an obstacle, the kick-out makes initial contact and pushes the rear corner of the vehicle away from the obstacle, preventing body damage to the expensive rear quarter panel.

Section 2: Skid Plates—Protecting the Vitals

Skid plates cover the underside components that sit between the frame rails—the things that stop spinning when they hit something hard. While stock Jeeps come with basic sheet metal guards, serious off-roading demands thick, aftermarket armor for crucial components.

The Hierarchy of Protection: Beyond the Belly

A comprehensive full-belly skid plate system is the ultimate protection, seamlessly covering the entire undercarriage from the engine cross-member to the transfer case output.

1. Oil Pan and Transmission: The oil pan is often exposed and made of thin stamped metal. A rock strike here can instantly drain your oil, killing your engine. This is a non-negotiable area to cover with a thick skid plate.
2. Transfer Case & Exhaust Loop: The transfer case and the low-hanging exhaust loop need dedicated armor. The transfer case can be easily cracked, and a damaged exhaust loop can restrict engine flow or tear off entirely.
3. Lower Control Arm (LCA) Skids: These small, inexpensive pieces of armor bolt or weld directly onto the lowest point of your axle housing, protecting the crucial mounting brackets for the lower control arms. Without them, a hard side impact can bend or tear off the mount, requiring an emergency trail fix or weld job. This is a vital, but often overlooked, piece of armor.
4. Steering Box/Steering Damper: A specific skid plate is often needed to protect the delicate steering gearbox and the hydraulic lines, which are vulnerable to forward-facing impacts.

Material Choice Deep Dive:

• Steel (The Brawler): Heavier and cheaper. Steel absorbs impact by deforming slightly, offering maximum protection from sharp, sudden impacts and resisting gouging when grinding across rocks.
• Aluminum (The Weight Saver): More expensive but significantly lighter. Aluminum armor reduces overall vehicle weight, which improves suspension performance. It's often thicker than its steel counterpart to provide similar rigidity but is less resistant to deep gouging from extreme rock crawling. Choose aluminum if weight savings for a better suspension feel is your priority.

Section 3: Axle and Driveshaft Armor

We spent all of Part 3 talking about expensive gear and shaft upgrades. Now, let’s protect those parts from the outside world.

1. Differential Covers—Reinforcing the Internals

Your differential cover is more than just a cover. The factory cover is thin and can deform, causing fluid leaks or impacting the gear mesh inside.

• The Upgrade: Replace both your front and rear covers with heavy-duty cast iron or fabricated steel covers. Look for Girdle Style covers—these not only protect the gears from outside impact but also feature internal bolts that reinforce the differential's main bearing caps, which prevents them from flexing under extreme load (especially useful with lockers and larger tires).

2. Driveshaft Protection

Your driveshafts are exposed, rotating components that can be ripped out by hitting a rock edge. Skid plates specifically designed to fit around the driveshafts (Driveshaft Loops or Skids) are cheap insurance against expensive driveline damage, especially for the rear shaft.

3. Knuckle and Ball Joint Gussets

While we mentioned them in Part 3 as structural upgrades, they are essentially the armor for the steering knuckles, preventing the "C" shaped knuckle from bending or peeling back when subjected to the tremendous leverage of large tires hitting obstacles. Gussets are mandatory if running 35-inch tires or larger.

Section 4: Inner Fenders—The Hidden Protection

When you install high-clearance flat fenders (which we’ll cover next), you eliminate the bulky, protective factory inner fender liners. This leaves your engine bay's vital areas—wiring looms, coolant reservoirs, air intakes, and brake lines—completely exposed to whatever your massive tires fling at them. Inner Fenders are the solution.