HZJ75 has had a six wheel drive (6x6)
conversion performed by 6x6 Australia.
The company is negotiating with builders of special purpose vehicles and
with with other companies over the supply of 6x6 conversion kits.
Airfield fire tenders are one obvious use, and armed forces
have "expressed interest".
The conversion involves two bits of magic.
The third axle is driven through the 2nd axle's differential,
and a viscous coupling, one way sprag clutch, and two
C.V. joints are incorporated to allow for articulation
and to prevent wind-up.
Rear suspension is by
"a patented load sharing coil spring bogie
with fully floating coil springs with a spring rate between
600 lbs and 1200 lbs per inch.
"The axial movement in the jack shaft is
only around 10-12mm at full 450mm wheel articulation."
This contrasts with the
load sharing rear leaf springs and the
non load sharing rear coils.
The 6x6 Toyota HZJ 75-78 carries up to 3.2tonnes and
has a gross weight of 5650kg.
"The resulting 6x6 is the only one available anywhere worldwide
with all of the following as standard fitment, 6 wheel drive
(full or part time), 6 wheel disc brakes, 6 wheel coil springs and
6 wheel steer [...]" [-6x6 Au]
"6 wheel steer" refers to the rear suspension geometry;
body roll changes the angles of the rear axles by small amounts
which is said to improve cornering greatly.
6x6 Australia do not only convert Landcruisers;
for example below is a Nissan Patrol that has had the treatment.
Apparently around 50 vehicles of various types have been converted to date,
the cost being about au$30K + GST, excluding any body work or tray