The Metal-Tech 4x4 Stage 2 Conversion Kit, which has our Gen 2 spring mount (Aluminum center and UHMW (Ultra High Molecular Weight plastic) CNC machined spring perch that correctly supports the rear suspension springs pigtail, considerably better than polyurethane.

100% in-house CNC machined center and spring perch, both from billet stock

Note: Countersunk center mounting bolt; this is so a Hex bolt head does not rip up the tip of your upper spring cone tips)

The stage 2 kit also includes our KeyCones; these are custom-made in the US and now US-patented cones that replace the OEM Toyota Rubber cones used in all Prado 120/150 rear coil springs. Toyota's design is for the cones to do two jobs. 1. Isolate the top of the rear spring from the frame mount. (noise inside, rust/ware top of the spring) 2. These are called 2nd springs by Toyota since they engage the top of the spring centering perch before you bottom out.

The MT4x4 KeyCones are dual durometer elastomers with a shock-absorbing tip that can be adjusted in height for lifted springs, so the cones correctly engage the axle before the axle bottoms out on the frame.

Metal-tech 4x4 invented the bolt-in conversion kit for GX's and was the first and only company offering these for several years. The original design, Steel Can center, big hex bolt on top, and polyurethane spring mount, worked and has been copied many times over. However, over the past 15+ years, we have found areas that could be improved. First, we CNC machined the lower spring support to provide more support to the bottom of the spring, all while keeping the spring as close to the center of the axle as possible. (Never want to lift the rear between the spring and the axle, this is why rear trim packers always go on the top of the spring, see the blog on our site on this) 

Next, we ditched steel with a CNC Aluminum center mount with the countersunk bolt. It took close to 3yrs developing the KeyCones, but we nailed it, so the duel rate not only works correctly, but we can now adjust the height for a lifted rear spring so they work as Toyota designed. This allows the cone to engage the top of the spring centering perch to soften a bottom out before the axle hits the frame-mounted bump stops. Again, Toyota calls the cones "Second springs" because of this. 

Mark Hawley

Founding Owner 

Metal-tech 4x4