MetalCloak True Dual Rate Rear Coils, 5.5in, Jeep Wrangler JK 4-Door, Pair

The rear axle on a JK has the harder job. It carries the luggage, the spare wheel, the towbar, sometimes a second tank — and on a vehicle built for the trail, heavy bumpers and armour as well. An ordinary spring answers all of that in one way: it settles.

True Dual Rate has two working zones in one spring. The lower, stiffer section carries the vehicle with all its load and holds ride height. The looser upper section comes into play as a wheel droops, letting it follow the ground. That is how a dual rate coil delivers stable ride height under load and articulation at the same time — something a single-rate spring cannot do.

High tensile chrome silicon steel, black powder coat. Easy to fit, 1–2 hours, no body modification.

This is exactly what dual rate coils are for — a real example

One of the manufacturer's customers put it better than any catalogue could. He was running a 4in lift, and after adding full skid plates and armoured fenders the vehicle simply sat down — the extra weight ate part of his lift. After changing to these coils, once the vehicle was loaded again, he had lost almost nothing.

That is the real problem with any JK built for the trail: armour weighs, and an ordinary spring cannot tell permanent load from momentary. The lower, stiffer zone carries that mass; the upper one stays free to work off-road.

⚠ Check which version you need — 2-door and 4-door take different coils

A 2-door JK is shorter and lighter at the back, so MetalCloak specifies its coils separately. These are for the 4-door (JKU) only, and for a 5.5in lift only.

When ordering, what matters is the number of doors, not just the height you want. Not sure? Get in touch and we will work it out.

A rear-axle set — what about the front?

These are rear coils only. The front for the same setup is part no. 7208 — we stock it. Coils are changed axle-pair by axle-pair; lifting only one end changes driveshaft angles and geometry, and leaves the vehicle sitting nose-down or tail-up.

Note one difference in contents: the front kit also includes 2 upper coil isolators, this rear one contains the coils alone. That is how the manufacturer splits them.

How the "virtual bucket" works

The dual rate design effectively lowers the coil bucket. The lower coils act as the load-carrying spring, while the looser upper coils behave like an extension of the bucket. The result: the coil stays seated even at full suspension droop, with no tendency to buckle.

Coil data — and how it differs from the front

REAR (SS-2041) Free length: 21½in (approx. 546 mm) Solid height: 8¾in (approx. 222 mm) Wire diameter: Ø 5/8in (approx. 15.9 mm) Inside dia., top: Ø 4 1/32in Inside dia., bottom: Ø 2 1/20in — strongly tapered FRONT (SS-2140) 22in / 8in, wire Ø 9/16in, bottom Ø 4 1/32in

The rear coil is shorter but wound from thicker wire (5/8in against 9/16in) and strongly tapered at the bottom, to suit the narrower rear seat on a JK. It is not the same spring as the front and the two cannot be swapped.

? Do not powder coat — it voids the manufacturer's warranty

This is the most important warning, and it applies to every True Dual Rate coil. The manufacturer states plainly that the baking process in powder coating can change the metallurgical properties of the coil and cost it its lift properties — the vehicle simply settles. Powder coating voids the warranty, stated or implied.

The coils arrive in a factory black powder coat and are meant to stay that way.

What these coils work best with

The manufacturer notes: True Dual Rate coils are engineered to perform best with Duroflex control arms and 6Pak or RockSport shocks. A spring with this much free length needs a shock with the travel to use it.

• Shocks: 6Pak BLACK for a 5.5in lift (rear part no. 7432R) or RockSport Long(er) — stocked here.
• Sway bar links: at 5.5in the factory ones are too short. Rear: kit 7241 with spacers. Front: 7221 (with the SWAY BAR button) or 7220 (without).
• Control arms: at 5.5in, Duroflex long arms are worth considering — individually or as complete systems.
• Rear geometry correction: at a large lift, look at the DB3 brackets or a long arm conversion.

The manufacturer also states that its components passed FMVSS 126 certification configured with 37in tires, full body armour and a suspension lift.

What's in the kit

• 2 × rear True Dual Rate coil

The rear kit contains no isolators — unlike the front kit (part no. 7208), where the manufacturer adds 2 upper isolators.

Technical data

• Application: Jeep Wrangler JK 2007–2018, 4-door, rear axle
• Lift: 5.5in
• Contents: 2 coils
• Material: high tensile chrome silicon steel
• Design: dual rate (True Dual Rate), designation SS-2041
• Free length: 21½in (approx. 546 mm)
• Solid height: 8¾in (approx. 222 mm)
• Wire diameter: Ø 5/8in (approx. 15.9 mm)
• Inside diameters: top Ø 4 1/32in, bottom Ø 2 1/20in
• Finish: black powder coat — do not re-coat
• Installation difficulty: easy
• Body modification: none
• Time to install: 1–2 hours
• Shipping weight: approx. 13.61 kg
• Country of manufacture: USA

Who they are for

For 4-door JKs built around a 5.5in lift — for large tyres and real off-road use. Especially for vehicles carrying heavy equipment: bumpers, a winch, armour, a roof rack. That is where the dual rate characteristic pays off most.

After a moderate lift instead? The 2.5in or 3.5in coils from the same family are the right ones — get in touch and we will give you the part numbers.

Installation notes

Fitting is simple: the manufacturer rates it easy and allows 1–2 hours with no body modification. In practice coils are changed together with the shocks, and it is the moment to check sway bar link lengths and control arm angles.

An alignment is mandatory after a ride-height change — the manufacturer recommends a specialist alignment after any MetalCloak suspension installation. Szekla4x4.pl is an authorised MetalCloak dealer with a workshop specialising in off-road suspension: we will fit the front-and-rear set, set the alignment and check clearances at full travel.

Why they are worth it

• They hold ride height under load — their biggest advantage on an armoured vehicle.
• Two rate zones: comfort and height without giving up articulation.
• They stay in the bucket at full suspension droop.
• Chrome silicon steel — resistant to sagging.

Frequently asked questions

Do they fit a 2-door JK?

No. These are 4-door only. On a 2-door, a 5.5in rear lift comes from part no. 7184.

Are front coils included?

No. This is the rear pair. The front for the same setup is part no. 7208 — we stock it.

Can I change only the rear?

We would not recommend it. Lifting one axle changes driveshaft angles and geometry — coils are changed as a set.

Are isolators included?

Not in the rear kit. The manufacturer includes them with the front kit (7208).

Can I have them powder coated?

No. The baking process can change the coil's metallurgical properties and cost it its lift properties. Powder coating voids the warranty.

Will they hold the height once I add armour?

That is what they are designed for — the lower, stiffer zone carries the load. One of the manufacturer's customers reported losing almost no lift after adding skid plates and armoured fenders.

Is an alignment needed afterwards?

Yes. The manufacturer recommends a specialist alignment after any suspension installation.