Land Rover Off Road Trials Vehicle Rebuild

The real challenge building this vehicle has been the fact that there is no specific donor vehicle, or plan to work to. Everything used was from Land Rovers but not one specific model type, its all a mix and match. Currently the vehicle is made up of mainly forward control chassis, Series IIA gearbox and body panels and a Range Rover V8 engine.

Mill Bug in action off road - videos

Series 2A Forward Control - Basic Vehicle

The basic vehicle comes from a Landrover Series 2A Forward Control Workshop vehicle. Bought from the army in the early 1990's this vehicle was a wreck with damaged body parts. The chassis however was sound. The forward control chassis is identical to that of a normal 109 Land Rover, except that it has an additional raised frame welded onto the existing ladder frame chassis. This frame was cut off the basic chassis. The chassis was then cut in half behind the third last cross member. A total of 9" was then taken out and the rear end was welded back to leave a wheelbase of 100". The rear cross member was also cut off at the second last cross member to increase the departure angle.

The standard ENV axles have been retained on the vehicle. These axles originate from Australia and were standard on the 109" forward controls due to their increased strength and carrying capacity over the standard Rover axles.

The rear PTO driven winch comes out of the original Forward Control. It is an original Land Rover hydraulic PTO driven winch. In the picture below you can see the 30l oil tank which holds the oil used for the winch operation. A proportional hydraulic valve block with simple forward/rear lever is mounted and operated through the seat box in the cab.

The Body and Shape

The classic look of the Series IIA Land Rover was without question the choice of body type, with the lights set in the grill. All these front body parts were readily available and sourced from different vehicles independantly. A forward control seat box had to be used due to its availability and the matching doors. Special mounting points were required to accommodate the seat box.

The original Forward Control firewall was used, despite suffering from some serious rust rotting, but it was structurally sound. Firewall outriggers had to be manufactured and mounted onto the chassis. To determine the exact positioning the body panels were temporarily mounted to make sure that it would all fit together. The rear body shape and design is not finalised yet. It will most probably take the form of a shortened LWB bakkie. Problem is that at the moment we don't have such a thing, but we are looking for one. If we don't find one we will probably go for a simple flat wooden or checker plate load bed with mud guards. The body panels were then vaguely prepared and sprayed with a 2K Land Rover Green.

The V8 Engine and Series 2 Gearbox

Various engine options have been considered for this vehicle. Everything from a 2.25 diesel to a 2.25 turbo charged petrol to the Rover 3.5L V8. We finally decided to go for the V8, because Brian had one removed from a Range Rover that he had bought recently. We needed something that would suite a large vehicle like this in terms of power and torque as well as sounding good, but ruggedness and longevity were important. We wanted to fit the V8 into the existing space without having to move the grill forward or changing the Series IIA look. We were able to move the radiator forward by about 2 centimeters, to accommodate the engine but keep the basic body shape. The problem was the front cross member which housed the steering relay which was exactly where the radiator had to go. So the solution was to cut out the cross member (leaving the steering relay intact. A substitute cross member was inserted into the front end of the chassis to provide the necessary rigidity.

The standard series II gearbox has been retained. It was chosen mainly due to its low cost and availability. It is the strongest of the series gearboxes and we are hoping that by not abusing it, it will be able to take the power and torque from the V8. Low ratio transfer gears from a forward control have replaced the standard gears in the transfer box. This was done to ensure a low enough low ratio for with the 900x16" tyres that will be fitted. The picture below also shows how the left centre part of the firewall was widened to make space for the exhaust manifold of the V8 engine.

The hydraulic pipes visible above are for the hydraulic winch, which is mounted at the back of the vehicle. The winch is operated with two levers one to couple the gear drive to the PTO in the gearbox and the other operates the valves for in and out spooling. The picture below shows the seat box mounted with the winch controls mounted through the seat box.

In the picture above the modification to the clutch slave cylinder is visible. With the V8 fitted the standard mounting position for the slave cylinder on the series 2 gearbox was taken up by the starter motor. So the next best option seemed to be to mount the cylinder inside the cab where there was some free space.

The engine fitted in fairly easily except for the left hand side exhaust manifold which sits very close to the chassis and firewall. However with the firewall modification mentioned earlier, and using the square type manifold,  it did fit in. The main problem was the total length of the engine. This problem was solved by moving the radiator forward slightly, and by removing the viscous unit and mounting the fan directly onto the water pump. The radiator is from a forward control hence a bit larger than normal.

This engine is fitted with a 4 barrel Holey on an Offenhauser dual port manifold carburetor which increases the fuel consumption and power, but reduces hassles and maintenance.

The Suspension and Brakes

The distinctive round shaped diffs are the ENV axles which were standard on the Forward Control. We are attempting to design the suspension in such a way that we will get maximum ground clearance and maximum articulation. This was achieved by mounting the springs on top of the axles. To soften the suspension and improve articulation, some of the blades from the leaf springs were removed. At the moment we are not sure exactly how many will provide the desired feel and performance so this will only be finalised once the vehicle is in use.

New shock absorber mountings had to be made at the rear. The rear axle above shows the modified shock mounting on top of the spring. Range Rover shock absorbers have been fitted to cope with the longer wheel travel. The large tank is the oil tank for the hydraulic PTO winch. 

The brakes are standard 11"x 3" as fitted on a Forward Control.

The Roll Cage and Body

The roll cage that we fitted was taken from Brian's camper 109. It originally fitted on the outside of the 109 thus sticking out making the vehicle wider. For the Mill Bug we decided to make it narrower and fitting inside the vehicle outline. So the front frame now enters at the top of the wing and is bolted to the firewall outrigger and to the windscreen mounting post.

The rear end of the cage was seriously modified to fit into the vehicle outline. At the back the cage bolts onto the seatbox and was then made to mount onto the chassis just behind the seatbox and onto the rear of the chassis.

The re-modeled roll cage now resembles a desert racing space frame which makes the 100inch wheel base look really short. It seems very sturdy though, and the design still allows for access to back for people and goods if need be. Above and below shows the 900x16.00 tyres fitted to forward control 2B rims. The total ground clearance of the axle below is pretty impressive. The lowest part of the chassis now really impressive with the door bottoms sitting almost at waist height.

The rear body was taken from the wrecked loadbed of a 110. We cut it up and custom fitted it to the rollcage. The rear floor was raised to make space for the winch. New mounting brackets were welded onto the chassis to mount the wheel arches onto. The rear end was finished off by cutting out the rear corner sections. Standard corner galvanised corner cappings were used.

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