Ron Moon's TroopCarrier gets Terrain Tamer GVM upgrade

With the TroopCarrier now wearing an ARB bull bar and a Carbon winch up front, and a Kaymar rear-step towbar down the back end, and with drawers and a water tank to come, I knew I had to upgrade the suspension.

Even though Toyota has upped the ante as far as GVM is concerned with this model, it is just a token upgrade, and like most people who set up their rigs for outback touring, I needed more in the way of load carrying capability.

In recent years parabolic springs have become a popular choice for those wanting to replace their standard leaf springs. Parabolic spring packs typically contain fewer leaves than normal leaf spring packs, so less unsprung weight, and they provide better flex and articulation, the latter sorely needed in 70 Series Cruisers.

In addition, the tapered design of each leaf in a parabolic spring pack allows forces to be more evenly distributed, and each leaf can work independently of each other with enhanced flex and, importantly, without sacrificing load-carrying capacity.

My son Trent has so far been impressed with the parabolic springs in his 79 Cruiser, having already run them on several tough trips while heavily loaded as part of his tour company’s travels to Cape York, across the Simpson and western deserts, and into the Victorian High Country. As a result, a set of parabolic springs for the rear of my Troopy were soon on my wanted list.

Lucky for me, Terrain Tamer released a GVM upgrade for the 70 Series Cruiser late last year that included parabolic springs. In this kit the GVM is increased from 3300kg to 3950kg. While the Troopy has a kerb weight of 2308kg, that does not include (as per normal with any kerb weight figure) any fuel, passengers or additions such as bullbars, dual batteries, etc.

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The Terrain Tamer GVM upgrade kit, designed in conjunction with well-known and respected Multridrive Technology (multidrive.com.au) based in Geelong, Victoria, includes new springs and shocks front and rear, along with a new sway bar for the rear, plus shackles and poly bushes. It also comes with all the necessary paperwork that needs to be completed as part of any GVM upgrade, and a sticker to go on the driver’s side B-pillar informing those who need to know of said GVM upgrade.

It’s a lengthy process to change a suspension with some heavy lifting involved that really necessitates a well set up workshop and equipment, so I left the job to the crew at Outback 4WD in Bayswater, Victoria (www.outback4wd.com.au).

The front suspension is relatively easy to fit with the original coil springs and shocks painlessly replaced with new Terrain Tamer items. The biggest issue at the front end is replacing the castor bushes on the trailing arms, which requires the use of a gutsy hydraulic press, both to remove the old bushes and to fit the new ones.

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Down the back a couple of people and a few support stands are required to safely extract the old leaf springs and fit the new parabolic springs. Once the new springs are in, the new shocks can go in and the new heavier duty sway bar can be fitted.

The Terrain Tamer TGS Series twin-tube shocks are bigger than the OE versions and they feature a 40mm bore and 20mm chrome hardened shaft. A bigger body allows more oil in the shock, which is a good thing as this minimises heat build-up while driving over corrugations and rough roads, while the shock ends feature double welded eyelets for added strength.

A multi-stage valving system is designed to provide a responsive but comfortable ride, and German-made nitrile seals keep the oil where it should be. The rear shocks are not only bigger but are more firmly valved than what would be required for a normal leaf-spring pack, as parabolic springs do not offer frictional resistance to oscillations of standard leaf springs.

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While we were at it, we also fitted a new steering damper to the Cruiser. What we didn’t have to fit as part of the GVM upgrade was bigger indicators; these are required on earlier model 70 Series to comply with ADRs, but our late-model rig already had the correct size lights.

With the new suspension fitted the Cruiser sits a lot taller than it did before, especially in the rear, but it will settle once the water tank and storage drawer system have been fitted. Nevertheless, even when empty, the ride quality is much improved compared to the standard setup, and I’m looking forward to loading up and hitting the tracks to see how it handles with some decent weight on board. According to Trent, I’m going to be impressed.

The Terrain Tamer shocks are covered by a three-year warranty while the parabolic springs are covered by an owner’s lifetime warranty.