Mark Allen installed a modified ratio gear kit in his 2011 Troopy for a better long-distance drive experience – here’s how it turned out.
Fifth gear on pre-2017 V8 70 Series LandCruisers are notoriously short, returning a relatively high revving and loud long-distance highway drive experience – not nice day in and day out!
In 2017, Toyota saw fit to change the 70 Series box ratios of the second and fifth cogs by 7 and 15 per cent, respectively. I could have shopped around for a later model than my 2011 Troopy box to slot in, but I didn’t really want my second gear to be higher than what I had, which is low enough and useable enough for towing and general off-road work with little need to change.
Enter the solution. A Terrain Tamer modified ratio gear kit for the gearbox, which leaves second as standard but changes fifth gear by plus 20 per cent – perfect! The complete gear set is a one-piece unit comprising first to fifth plus reverse cogs and is manufactured in Japan with hardened steel and a Rockwell rating of 62. That means it’s damn hard and high quality.
I dished out for the Terrain Tamer kit, had a gearbox mob pull down the box and stuff it full of the new kit, which effectively changed the fifth cog from 0.881 to 0.736 to provide a theoretical change of around 400rpm.
While 400rpm may seem a minimal drop, the long-term highway cruising fuel savings will make a difference to my hip pocket, albeit it won’t pay for itself anytime soon. However, the noise difference makes up for that. Given that the 70 Series are commercial vehicles with little to no soundproofing as standard, the intrusive road and driveline noise is annoying over time. Obviously, this lowering of revs can’t ever convert my Troopy to a 200 Series luxo-barge, but it has helped considerably with the newly installed modified gear ratio kit.
Standard gearing in my Troopy saw it clocking 2200rpm at 100km/h and 2500rpm at 110km/h, compared to the Terrain Tamer kit, returning just 1800rpm and 2100rpm at 100 and 110km/h respectively.
That confirms perfectly the theoretical reduction of 400rpm.
Any upping of gear ratios puts more stress on the driveline with potential over-gearing, creating more labour for the engine. This can cause higher fuel usage and less ability to use that higher gear set if the engine can’t deliver enough torque at the right revs. The correct modified ratio gear kit mitigates these risks.
Given I have a DPChip that can be turned off, this allowed me to test my engine close to standard, other than the three-inch TaipanXP exhaust system and 33-inch rubber. Indeed, the engine struggled a little on long and steeper hills on the highway at 100 and 110km/h. There were occasions when I needed to downshift to fourth, which I had always been able to tackle in fifth with standard gearing.
With the DPChip turned back on and set at position three as per usual (which was deemed safe and reliable via the installer), returning 131kW and 747.5Nm, there was little need to fiddle with the gearstick over the same roads. Towing a camper or caravan has seen more downshifting than normal, and that’s where even higher returns of safe tuning will help. That leaves you with a taller fifth that can be used most of the time but requires the occasional downshift to prevent labouring. The modified ratio gear kit has shown its value in these scenarios.
All up, while this modified ratio gear kit may not pay for itself for a very long time, the pleasure and security of a quieter cabin via the lower-revving engine was well worth the exercise.
my mind boggles that a V8 would sit on 2100rpm @ 110kph, people who drive these things deserve an award for perseverance.
my vdub will click into 8th doing 1400rpm at 105 towing the 2.8t van and use 15l/100km, albeit sometimes up a hill it kick back and will get up to 2000rpm…
I found a similar trick for my N70 Hilux but didn’t have to pull the drivetrain apart to achieve better gearing. It came from the factory with 15″ wheels. At 110kph it was loud and revved it’s guts out. When the tyres wore out I tried a mates 16″ wheels and the difference was amazing. Extra ground clearance, lower gear ratios and lower fuel consumption. I then tried some 17″ wheels and that’s where I’m stopping. Towing the 2T camper trailer at 100kph in fourth is quiet and carefree with only the occasional change down for a hill. Long sand climbs are much easier with the bigger tyres giving more footprint and higher speed in low range. I have no idea why Toyota put the small wheels on it to start with.