Metalcloak technology — what the names actually mean
Metalcloak uses its own naming for almost every suspension component. This is not marketing stuck onto generic parts — each name refers to a specific engineering solution. Below is what each one does and when it matters in practice.
| Design | Range of motion | Vibration damping | Maintenance |
|---|---|---|---|
| Rubber-and-steel bushing (OEM) | limited | good | maintenance-free, but wears quickly once lifted |
| Heim-style joint | large | none — transmits noise | needs inspection and replacement |
| Johnny joint / rebuildable | large | moderate | needs periodic greasing |
| Duroflex (Metalcloak) | 68° | good — Kevlar-reinforced elastomer | no greasing |
Duroflex joints
Vulcanised elastomer reinforced with Kevlar fibre. 68° of articulation versus roughly 40° for conventional joints, with no greasing and no metallic knock.
Duroflex is Metalcloak's own answer to both rubber-and-steel bushings and heim or johnny-style joints. An elastomer vulcanised with Kevlar fibre carries load while damping vibration, so the arm can work at a steep angle without binding and without transmitting noise into the body. The manufacturer quotes 68 degrees of movement against roughly 40 degrees for conventional designs. In practice that means more suspension travel at the same lift height and no periodic greasing — a real argument in a climate where the vehicle sees road salt.
Duroflex joints
Vulcanised elastomer reinforced with Kevlar fibre. 68° of articulation versus roughly 40° for conventional joints, with no greasing and no metallic knock.
True Dual Rate coils
Extra-long chrome steel coils with two spring rates: soft at the start of travel, firmer under load.
Instead of a single fixed rate, the spring works in two stages. The first part of travel is soft, giving on-road comfort and better wheel contact at low speed off-road. Under deeper compression — in a rut, with a loaded expedition build, or during faster driving — the rate stiffens and limits bottoming out. The coils are longer than typical lift springs, so they stay seated in their perches when the suspension droops fully.
True Dual Rate coils
Extra-long chrome steel coils with two spring rates: soft at the start of travel, firmer under load.
Durotrak track bars
A patented two-piece elastomer bushing allowing full vertical rotation while damping noise and vibration.
The track bar works at an unusual angle on a lifted vehicle and is the usual source of knocking and steering wander. The Durotrak bushing was designed to allow the full vertical range of motion without introducing lateral play. The result is a stable line without giving up comfort — no need to move to rigid heim-style ends that transmit every vibration into the cabin.
Durotrak track bars
A patented two-piece elastomer bushing allowing full vertical rotation while damping noise and vibration.
RockSport and 6Pak shocks
RockSport in several damping variants, including a 2.5" reservoir version. 6Pak is a patented maximum-travel design.
Game-Changer systems can be configured with different shocks. RockSport comes in several variants with different damping characteristics, up to the 2.5" BLACK reservoir version intended for heavier builds and faster driving. 6Pak is a patented design focused on maximum travel. Shock choice depends on built weight, tyre size and whether the vehicle mostly sees tarmac or trails — a conversation worth having before ordering, not after.
RockSport and 6Pak shocks
RockSport in several damping variants, including a 2.5" reservoir version. 6Pak is a patented maximum-travel design.
Frame-Built bumpers
Modular steel construction bolted to the frame, configurable from a narrow base up to a full centre section with winch mount.
Frame-Built bumpers are modular: a base bolted directly to the frame, to which side sections, a centre skid, a winch mount or light tabs are added. That lets you start minimal and extend the bumper as the build develops, rather than replacing the whole part. The #2201 fits both Wrangler JL and Gladiator JT; #1401 fits the JK.
Frame-Built bumpers
Modular steel construction bolted to the frame, configurable from a narrow base up to a full centre section with winch mount.
Overline fenders
High-clearance tube fenders, also available in aluminium. They clear large tyres without cutting the body.
Overline answers a problem that appears with every serious lift: at full compression the tyre meets the fender, forcing either reduced travel or cutting sheet metal. Overline tube fenders raise the arch line while keeping the tyre legally covered. The aluminium version does not corrode, which matters on vehicles driven through winter.
Overline fenders
High-clearance tube fenders, also available in aluminium. They clear large tyres without cutting the body.
Frequently asked questions
What is a Duroflex joint?
Duroflex is Metalcloak's own joint made from vulcanised elastomer reinforced with Kevlar fibre. It replaces both rubber-and-steel bushings and heim or johnny-style joints. The manufacturer quotes 68 degrees of movement against roughly 40 degrees for conventional designs, with no greasing required.
How does a True Dual Rate coil differ from a normal lift spring?
A normal spring has one fixed rate. True Dual Rate works in two stages: the early travel is soft, giving comfort and better wheel contact, and under deeper compression the rate stiffens to limit bottoming out. The coils are also longer, so they stay seated at full droop.
Is Metalcloak suspension suitable for daily driving?
Yes — it is one of the brand's main arguments. Two-stage coils and vibration-damping elastomer joints keep a lifted vehicle comfortable on tarmac, unlike setups built around rigid heim-style joints.
Do Duroflex joints need greasing?
No. That is a meaningful difference from johnny-style joints, which need periodic service. In a climate where the vehicle sees road salt through winter, having no grease points genuinely reduces maintenance.
Which shock should I choose: RockSport, 6Pak or Fox?
RockSport is the default choice for most road-and-trail use, with the 2.5" BLACK reservoir version for heavier builds and faster driving. 6Pak is a patented maximum-travel design. The choice depends on built weight and tyre size — we are happy to advise before you order.