As the original designer for the bolt-on rear airbag conversion kit for our GX's, going back before most knew what the GX's really were, we have experimented with several variants of a conversion kit and refined the kit we build now for maximum performance. 

Over the past years, as more companies decided to duplicate the MT4x4 center bolt conversion mount concept, some have added the "extra feature" of being able to add lift by the conversion kit at the axel. Sounds great right? Yet you will find no one in our industry, including the very companies that offer the "added lift" conversion kits, make or sell coil spring trim spacers/packers that are designed to go at the BASE of a coil spring at the axle. All coil spring trim spacers/packers or full-on lift spacers are designed to go to the TOP of the coil spring at the frame mount. There is a reason for this. 

Solid axles rotate in an arc as they droop down away from the frame. For the rear of the GX, this swings forward on the arc. This arc also includes the spring mount, so it is not pointing up, but more back off the truck at full arc. Adding a spacer under a coil spring at the axle will result in the spring wanting to kick off the now-leaning spring perch. Putting a spring spacer/trim-packer at the TOP of the spring between the top mount at the frame, that is, the stationary and the widest point of the spring. This is the ideal point for putting a spacer with a coil spring, as the frame mount point is the widest and most stable point for the spring to flex with the axle arc. 

So, no, we do not intentionally add lift to our conversion kits. We keep them as low as reasonable. In addition, our current 2.0 conversion kits feature a UHMP spring perch that is CNC machined in-house. This special plastic provides far superior spring support vs. polyurethane yet still provides vibration/noise isolation that metal-to-spring mounts just can't do. We actually off road the parts we design and build. They are designed by real-world experience and built with a purpose. 

Video on the MT4x4 2.0 coil conversion kit

We build them 100% right here in the USA, in-house. 

Mark Hawley 

Founding Owner 

Metal-tech 4x4