THE DIRT LOCKER
JIMMY’S HILUX GETS SERIOUS WITH A TJM PRO LOCKER.
AFTER ONE of our off-road trips to the Glenreagh region north-west of Coffs Harbour, it became evident on more challenging, rutted-out hill climbs just how much the Hilux and I were relying on momentum rather than utilising the torque and traction that would be available if running a locking differential.
When off-roading on uneven terrain, it is quite common to have either a front or rear wheel lose traction or even lift off the ground. When this happens the power will always take the path of least resistance and head to the tyre that is losing traction or in the air, leaving the opposite tyre, which is actually the one needing power, with limited to no power. This is where diff locks come in handy; with a flick of an in-cabin switch you can lock the differential, forcing both wheels across an axle to rotate at the same rate to deliver equal power to each of them, but more importantly delivering power to the tyre actually planted on the ground.
There are a few types of lockers (mechanical, air and electrical) and all essentially perform the same task but are engaged either through mechanical means, via an air compressor or via an electromagnetic mechanism. In most cases of lost traction you will generally have at least one front wheel and one rear wheel firmly on the ground, so either a front locker or rear locker is going to add significant traction by locking either axle.
There is great campfire debate about whether a single locker should be in the front or the rear. The more weight you carry over an axle increases the traction available when locked, so if you carry significant weight in the rear this could be your best option. There is also the push/pull debate when comparing front and rear, with the belief it is easier to pull the vehicle up over challenging terrain with a front locker compared to pushing from the rear.
The most relevant point to this Hilux build is the stress placed on the more complicated front drivetrain when the diff is locked. As the Hilux came to me with more than 150,000km already on the clock I didn’t want to place further stress on the front diff, CV joints and steering components that I don’t have a solid history on, so I opted for a rear Pro Locker from TJM.
TJM’S Pro Locker is an innovative airactuated locker running a unique onepiece cross shaft (instead of the usual three), hardened thrust washers and large pinion gears. It’s a solid bit of kit at $1499 and is covered by a five-year warranty. The Pro Locker comes with a small dedicated air compressor ($229) for engaging the locker, and we mounted this in the cabin behind the rear seats, running the airlines under the body and the switches up front.
APAC 4x4 on the Sunshine Coast fitted the locker in half a day with no issues. At the time of writing the weather here was on the wet side, with a lot of flooding around my favourite proving ground, so the locker is installed but I’ve yet to take it out and put it through its paces.
The Hilux will be getting some long overdue new wheels and rubber by next issue, and hopefully some time on my favourite uphill tracks. Now that it’s equipped with its new Pro Locker, I’ll let you know how it tackles some of the more challenging climbs where it’s struggled in the past.