MetalCloak Duroflex Front Upper 4-Link Long Arms, Jeep Wrangler JK/JL and Gladiator JT

The front upper arms set the pinion angle and keep the front end from walking at full compression. In a long arm setup they are usually what decides whether you can get back to correct caster after a lift — which is why they are adjustable.

1¼in DOM tube with a 3/16in wall, CNC formed for clearance, a forged adjustable end with a Duroflex joint at one end and a 1/4in plate clevis at the other. The Duroflex joint gives over 34° of misalignment with factory-bushing comfort — without the clunk that ordinary flex joints cost you.

The install is simple: 1–2 hours, bolt-on, with no modification to the vehicle.

⚠ Check fitment before ordering — the manufacturer's data is inconsistent

Honestly, because it matters on a purchase of this size. MetalCloak states compatibility differently in two places:

• The catalogue product name reads "Jeep JK/JL Wrangler, JT Gladiator … Pair, 4-Door" — so JK, JL and Gladiator, four-door versions.
• The specification table, however, lists only "2018+ JLU Wrangler".

The broader reading is supported by the catalogue name, the page's structured data, and by the fact that the manufacturer's own dimensioned drawing is filed under a name containing "JK-Wrangler". The opening paragraph, meanwhile, is old copy written for the Gladiator alone. We have taken the broader reading, limited to four-door vehicles, in line with the product name.

Running a two-door JK, or not sure? Get in touch before ordering — we will ask the manufacturer and confirm. We would rather not have you sending the arms back.

⚠ These are arms only — and they need mounts

This item is a pair of front upper arms and nothing else. In a long arm setup the front upper arm attaches to a separate frame bracket, which is not included here — MetalCloak makes it in two versions, bolt-on and weld-on.

If you are moving to a front long arm setup for the first time, the right purchase is the complete front 4-Link system, which we stock — it contains the upper and lower arms and the full set of brackets. The arms alone make sense for repairs after damage, for replacing arms in a finished setup, or for a build on your own brackets.

The Duroflex joint — this is what you are paying for

MetalCloak's patented joint: a vulcanised elastomer reinforced with DuPont™ Kevlar® fibre, self-centring, with a true bearing surface on the outside of the bushing.

• Over 34° of misalignment per joint – against the handful of degrees a factory bushing allows.
• Vibration damping and self-centring – ride quality stays at factory level. Ordinary flex joints are bought at the price of noise; here there is no such price.
• Absorbs micro-movements – the millions of small rotational movements of daily driving that cause the micro-wear which destroys ordinary flex joints.
• No binding of the control arms – the outer surface of the bushing works as a bearing and breaks free when called for.
• Maintenance free, yet rebuildable – pull the bushing, clean it, add Teflon-impregnated silicone grease, reassemble.

Construction

• 1¼in DOM tube with a 3/16in wall – CNC formed, with a bend for clearance.
• Forged adjustable end – 37% higher fatigue strength than cast parts, 1in–1/4 UNF thread, precision locking nut.
• 1/4in plate clevis at the opposite end — for the factory style of upper arm mounting.
• Gold zinc plating over the whole arm.

What's in the kit

• 2 × front upper long arm (a pair)

The kit contains no frame brackets and no hardware.

Technical data

• Application: Jeep Wrangler JK/JL and Gladiator JT, four-door versions, front axle, upper arms
• Contents: a pair of arms
• Tube: DOM ø1¼in (31.8 mm) with a 3/16in (4.76 mm) wall, CNC formed
• Length: 26¾in (approx. 679 mm), adjustable
• Adjustable end: forged, 1in–1/4 UNF thread, precision locking nut
• Joint: Duroflex, vulcanised elastomer with DuPont™ Kevlar® fibre
• Misalignment: over 34° per joint
• Opposite end: 2in clevis in 1/4in plate, for a 1/2in bolt
• Finish: gold zinc
• Installation difficulty: easy
• Body modification: none
• Time to install: 1–2 hours
• Shipping weight: approx. 6.8 kg
• Country of manufacture: USA

Who they are for

For vehicles already running a front long arm setup that need the upper arms replaced — after damage, or during a suspension rebuild. And for anyone who wants caster adjustment without rebuilding the whole setup: the install needs no work on the vehicle, unlike the front lower arms, which require cutting and welding.

Installation notes

MetalCloak rates the install as easy and allows 1–2 hours, with no body modification. The length adjustment is there to set the pinion angle — that has to be done after fitting, followed by an alignment.

Szekla4x4.pl is an authorised MetalCloak dealer with a workshop specialising in off-road suspension — we will fit them, set the caster and do the alignment. Send us your configuration, especially if you run a JK.

Why they are worth it

• Pinion angle adjustment that factory arms do not offer.
• Factory-bushing comfort with Duroflex range of movement.
• A forged end with 37% higher fatigue strength than a cast one.
• Bolt-on in 1–2 hours, with nothing modified on the vehicle.

Frequently asked questions

Do they fit the Jeep JK?

MetalCloak's catalogue name lists the JK alongside the JL and Gladiator, but the specification table on the same page lists only the JLU 2018+. We have taken the broader reading, limited to four-door vehicles. For a JK — especially a two-door — get in touch before ordering and we will confirm with the manufacturer.

Is this a complete front long arm conversion?

No. It is a pair of upper arms only. Frame brackets and lower arms are also needed — those are part of the complete front 4-Link system, which we stock.

How many Duroflex joints does each arm have?

One. The other end is a 1/4in plate clevis — that is how the front upper arm is built.

Does fitting require welding or drilling?

No. MetalCloak specifies: no body modification, easy install, 1–2 hours.

What is the length adjustment for?

To set the pinion angle (caster), which stops being correct after a lift. Factory arms offer no such adjustment.

Do the Duroflex joints need servicing?

Not routinely — MetalCloak describes them as maintenance free. A rebuild means pulling the bushing, cleaning it, adding Teflon-impregnated silicone grease and reassembling.