Tales of a 3.9 litre Tdi Bushie Ute

Drive Train

“Be happy while you’re living, for you’re a long time dead.” – Scottish proverb

 

The donor Land Rover 120 ute came without the Isuzu 4BD1 engine and Land Rover gearbox, which the previous owner had transferred to his Range Rover. A replacement Isuzu 4BD1T engine and MXA6-R gearbox was purchased from a Sydney truck wrecker.

Bushie Engine

Before the replacement engine was installed in Bushie Ute the rotating parts were balanced, new valve springs and head studs fitted, and the fuel injection pump and injectors were serviced. A new alternator and starter motor were fitted.

The turbocharger needed an overhaul, but because it was an old design and best suited for the 7000 kg GVM truck application, running near maximum power and speed all day, it was replaced with a new turbocharger that provides better drive-ability, particularly at lower engine speeds.

Read more about Bushie Ute’s engine

1989 Isuzu 4BD1T engine, 3.9 litre diesel

1989 Isuzu 3.9 litre 4BD1T four cylinder diesel engine. Turbocharged version of the stock 4BD1 originally fitted by Jaguar Rover Australia (JRA)

 

Borg Warner Turbocharger

New Borg Warner turbocharger to replace the old worn Garrett T2

 

Bushie Gearbox

This photograph shows the six speed Isuzu MXA6-R gearbox alongside a five speed Land Rover R380 gearbox from a Land Rover Discovery.

Read more about Bushie Ute’s gearbox

Isuzu MXA-6R (front) Compared to Land Rover R380 (back)

Six speed Isuzu MXA-6R, manual gearbox (front), compared to five speed Land Rover R380 (rear)

 

Bushie Transfer

The transfer case installed in Bushie Ute is an Atlas II with 5.0:1 ratio low range gears.

Read more about Bushie Ute’s Transfer Case

 

Bushie Axles

Front and rear axle assemblies were going to be Y61 (GU) Nissan Patrol, because the Y61 rear diff is centred, which suits the centred rear output of the Atlas transfer case. However it was decided to retain the axles that were fitted to the four seat bushie at an earlier time. They came from a Toyota HZJ105R and the diff in the strengthened front axle housing has been changed to Nissan H233B to address the one weakness of the Toyota axles. In most other areas, they are better than Nissan Y61. They have ARB air lockers and the reduction ratio is 4.11 to 1 in the front and 4.1:1 in the rear axle, though both will be changed to 4.875:1 to make better use of the ratios in the Isuzu gearbox with its tall sixth gear.

These axles and differentials are stronger, the brakes are better, the turning circle is better, and the increased track width provides greater stability than the donor Land Rover axles. The following compares some important details for these axles:

  • Load rating front: 1390kg Toyota, to 1300kg Land Rover
  • Load rating rear: 1790kg Toyota, to 1900kg Land Rover
  • Track width front: 1620mm Toyota, to 1486mm Land Rover
  • Track width rear: 1615mm Toyota to, 1486mm Land Rover

Some other details comparing the Toyota HZJ105 Landcruiser wagon to the donor Land Rover 120 cab chassis:

  • Tare weight: 2440kg, to 1760kg
  • GVM: 3180kg, to 3200kg
  • Final drive ratio: 4.3:1 (changed to 4.1:1), to 3.54:1
  • Wheelbase: 2850mm, to 3040mm
  • Front overhang: 895mm, to 643mm
  • Rear overhang: 1145mm, to 1001mm
  • Overall length: 4890mm, to 4684mm
  • Overall height: 1920mm, to 2035mm
  • Overall width: 1940mm, to 1784mm
  • Turning circle: 12.0m, to 13.9m

Read more about Bushie Ute’s Axles

 

Bushie Gearing

The following tables and charts show the overall gear ratios, and road speed with LT315/75 R16 tyres, for a range of engine speeds in each gear combination. Note: these results are calculated for a final drive ratio of 4.875:1 Low Fourth and High First are practically identical, Low Fifth and Sixth split High First and Second.

Road Speed vs Engine Speed

Read more about Bushie Ute’s Gearing