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OKA NT and Camper - Flops and Improvements

After some years of travelling around Australia, a few things were missing; others were not worth to be built. Missing things have been added; others have been removed or replaced and improved.


  • HF-Radio Barrett 2050 and Antenna Barrett 910
    Even so the Barrett 2050 is top notch, the reception quality is far below expectations. As non-native English speaking person it is very difficult to understand anything on the radio because of the terrific back noise.
    It was planned to use the radio to report our position to VKS-737 on a daily base while travelling in the far outback. Since transmission/reception is so poor one is never sure if he is able to report the new position the next day. The impossibility to report the position could possibly start an unnecessary search operation.
    We now fully relay on our superb Iridium Sat phone. Be aware that it has to be an Iridium phone. The GlobeStar system is known to be very unreliable.
  • Bead Locks
    The Bead Locks are self-destroying should the tubeless tyre slips on the rim when braking hard. The valve of the inner tube is then ripped off. Since the air pressure in the tubeless tyre and the inner tube is more or less the same, the error is not recognisable. Also when the beadlock turns the inner tube covers the tubeless tyres valve making it impossible to deflate the tubeless tyre for gravel or sand.
    Fixing a beadlock on a bolt together rim is a pain in the bum.
  • Honda 10i Power Generator
    With 440W solar panels and 380Ah batteries there is no need for an additional generator in Australia. For other countries like South America, Canada a.s.o. it is probably a different story, but instead of carrying a generator we can also run the motor for 1 hour to give us again power for a full day.
  • Intelligent battery charger for house battery
    The battery charger installed between the alternator and the house battery drastically limits the charging power. It also inhibits cranking the motor with the house batteries using OKA's pre-wired switch. The Smart Relay installed by OKA as part of the dual battery option works much better even so some improvements have to be made to the wiring.
  • Umbrella sun shade
    The insulation of our back-section, the huge windows and the large roof hatches keep the inside of the back-section cool enough to stay indoors even when it is hot outside. Due to the large windows one doesn't feel locked up when staying inside.
    So the umbrella was seldom used.
    In addition, in Australia the unpredictable high winds (Willy-Willy) are too strong for the big umbrella. They could destroy it.
  • Compass in Driver Cab
    There is too much iron ore all over in Australia's earth. The compass reading even so correctly compensated was often wrong by up to 90°. It was often more a "miss-leader" than a compass.
  • PullPal earth-anker
    Even the large and heavy "PullPal" earth-anchor doesn't do the job for us in soft terrain. It is unloaded. In the future we will, as many others too, bury our spare wheel and the sand boards as an anchor point.
  • Fuel Cell
    The added EFOY 2200 fuel cell has been removed again. Its weight and power stands in no relation to its price. We only bought the fuel cell because I wrongly interpreted the specification. The power of ordinary power generators is always given in Watt (W), the power of the fuel cell (EFOY 2200) is given in Watt-hours (Wh) 2200W = ~91Wh. This is about as much as the power supply of a laptop, but it weighs about 20kg and costs a few thousand dollars. Also fuel cells require extremely refined Methanol which is neither easily available in Africa nor in South America.
  • All diff locks eliminated
    On the OKA-NT axles the diff locks are on the drive shaft. All diff locks have been eliminated mainly to enable the possible replacement of a twisted drive shaft. If the drive shaft cannot be removed from the axle the whole axle must be replaced. We cannot afford this risk.


  • Door Step Covers
    OKA's door steps have been covered so nobody can climb up the car while it is slowly rolling. This is a theft and hold-up protection. According experiences have been made by Ruedi in 1973 in Italy.
    It is absolutely unnecessary in Australia.
  • Security bolts on main door
    It is theoretically possible to cut open the hinges of the lower door and then open the door with brute force. The two additional steel pins prevent this now. This is a security measure for RoRo ferries.
  • Hub Breathers
    OKA's hubs are vulnerable to water entering when wading through cold water. Front and rear axle-hubs are air-wise separated from the axle differentials, but the hubs have connection points for separate breathers.
  • High Altitude Kit for Eberspaecher Coolant Heater
    In preparation to South America where we will drive up to 4600 m altitude a high-altitude-kit (i.e. a different diesel pump) has been added. It should work to an altitude of 2750 m. Even with this kit installed it is very uncertain if our floor heating will work.
    2013: The "old" Eberspaecher we have installed works up to 3000 m. The solution would be ether to install a newer type from Eberspaecher or a heating from Webasto. The one from Webasto definitly works on much higher altitudes as travellers confirmed.
  • Bleeder pump
    It is very, very difficult to bleed the fuel system on an OKA NT. A pump has been added before the motor (i.e. ECM and Fuel Filter).
  • Heater Blower in Back-Section
    Heating the back-section using a floor heating is initially very slow. To speed-up the process a coolant driven heater blower is installed under the rear seat (Eberspaecher Helios 2000).
  • LED Lights on widow frames to illuminate the Back-Section
    Using any lights inside a camper always attracts a lot of flying objects who desperately want to enter the camper to get to the light source. The only way to avoid this is by position the light outside of the camper.
    We added LED-lights to the lower part of the wind-out windows so if we open the windows the LEDs are about 50 cm outside of the camper shining into the camper. All flying nuisances fly now against the mozzie screens then turn around and fly towards the light source. Even objects already in the camper try to escape through the mozzie screens. The lights work perfectly.
  • Cloth Triangles on Windows and Door
    Cloth triangles have been added to the side of the window lids as well as to the side of the upper door. This prevents rain to pour into the camper if the windows are open. There must be strong wind and the rain must fall in an angle of 45° to get into the camper. Especially in hot and humid areas we can now let all windows open when rain falls so we can catch every breeze.
  • Window Cover Locks
    The window covers can now be bolted to the camper body from inside the camper make it impossible to open the covers and windows from outside. This is for additional security while shipping the truck to other continents.
  • Protection of Roof Hatches
    Both roof hatches can now be bolted shut from inside using metal plates. This is also a measure for improved security while the truck is on a RoRo ferry.
  • Additional security for OKAs main doors
    Mainly for Africa and South America the side windows are now shatterproof and additional padlocks on the doors make it hard(er) to break into the cab.
    2013: Even with the additional protection it takes a professional no time to open the doors.
  • Electric Fan
    An electric fan has been added in the back-section to get more air circulating through the camper mainly during hot nights. The back-section is fantastically isolated and keeps the heat out during the day but on the other hand the warm walls prevent the camper from cooling down fast during the night.
  • Cloth Hanger in Entry Section
    A cloth hanger has been installed in the shower pan to hang wet cloth.
  • Second Pump for Dual Water System
    We normally store potable water in 2 steel tanks. If we don't get good water after emptying one tank, we can fill the empty tank with bore-water. We then connect a second pump to that tank and switch the system into 2-water mode. The shower and the warm water tap in the sink are now delivering bore-water which bypasses all filters. Only the cold water tap of the sink still delivers filtered potable water.
  • New Spare Wheel and Sand Board Carrier
    A new version of a spare wheel carrier has been built. It also holds the 6 fibre glass enforced sand boards. In addition the carrier is used to stabilise the back-section against sideways movement.
  • Electric cooking plate
    An electric 240V~/1500W cooking plate has been bought. It will be used to cook short meals on altitudes unsuitable for the Wallas diesel stove.
    2012: The power consumption was too much for our inverter. It broke down. We replaced the cooking plate with an induction type cooking plate of max. 2000W. In position 5 which uses 1200W it cooks the same amount of water in half the time. This means it uses only 50% of the power of the previous cooking plate.
  • Exhaust brake
    We are the first OKA-NT fitting an Exhaust brake to increase the brake power of the motor.
  • Interval wiper system
    We install a "Hella" interval wiper system, because our pre-production truck doesn't have one. The installation works without any problems.
  • Heater blower for floor heating
    The floor heating works fine, but it takes too long to heat up a cold back-section. We add an "Eberspaecher Helios 2000" Heater Blower. It also takes its energy from the water in the floor heating and turns on as soon as the water reaches 30°C. The room heats up within 4 minutes. Once the room reaches its final temperature the heater blower is t turned off together with the heating. The original start relay for the fan had to be replaced by a Hella time delay relay to delay the start by 8 minutes. The diesel heater requires a 10 minute heat cycle to avoid getting sooty.
  • Shut-off valve for the floor heating if motor is used as heat source
    Propre adjustment of the heating is impossible if the motor is used as heat source. Either the room gets far too hot or it stays cold. A shut-off valve has now be installed in the heat pipes. It is controlled by the thermostat of the diesel heater. The water-flow as well as the heater blower are stopped if the desired room temperature is reached.
  • 4 snow chains
    After the positive experiences we had with our 2 snow chains in Africa for md driving we added 2 more chains. Now we can fit all wheels with chains.

Changed, Improved and Replaced

  • Leaf Springs
    The top 2 leafs of the front spring packages and the top 3 leaves of the rear spring packages have been changed from 8 mm to 10 mm to be able to reduce the air pressure in the air bags and to prevent the leaves from breaking.
    2009 we broke both front eyelets of the rear springs.
    2012: In Switzerland the whole suspension has been replaced. It is custom made for our weight. The added airbags have been removed.
  • OKA's Shackle Pins
    OKA's original shackle pins consist of a 16 mm greasable pin and steel converter bushes to the 24 mm bronze bushes. Greasing that system doesn't work and the shackle pins are known to break regularly.
    We replaced the original pins by 24 mm greasible Hino pins; the ones that belong to the bronze bushes anyway. OKA, after improving our truck, improved their pins too. OKA's new pins are now even better than ours. Needless to say we are proud of what we achieved!
    2012: Shackle pins and bushes have been replaced and improved again in Switzerland.
  • Right front leaf spring package
    On the axles of the new OKAs (model NT) there is too much sideways play between the front axle housing and the right spring package. Eliminating the play using a peace of sheet metal helps for a more stable steering.
  • Steering Damper
    The steering dampers originally mounted on our OKA were simply not up to the task. The whole truck was often dangerously shaking between 40 and 80 km/h. The shaking never occurred anymore since we changed to a much stronger steering damper. OKA now also uses much stronger steering damper.
  • Chassis Mounts for Back-Section
    The OKA chassis flexes very little, but still much more than predicted and transmits too much stress into the back-section. Longer screws and another rubber damper have been added to the original mounts so the back-section can separate more from the winding chassis.
  • Batteries
    All acid batteries have been replaced by maintenance free AGM batteries. The starter battery is 12 V with 100 Ah; the house batteries are 2 x 6V with 380 Ah
  • Shackles and Snatch Block
    All Shackles have been replaced by 8.1 t SWL shackles from ARB. We bent all other shackles we had so far even the ones being labelled for 11 t. The snatch block from Superwinch has been replaced by the model 9000 snatch block from ARB.
  • Solar Controller
    We currently use a Plasmatronics PL40 solar controller after the old one broke. It most likely failed because somebody welded on the truck without disconnecting the batteries.
  • UHF Antennas
    The long, impressive and sturdy looking fiberglass antennas mounted on the bull bar constantly broke internally without any visible outer damage. Looking inside such antennas revealed the building quality as a disgrace. It is poor luck they ever work. "Mobile-One Antennas" are a very bad example. We replaced the antennas with a very short "No-Brand" antenna, placed it on top of the roof and it works perfect ever since. Except when I rip it off on a branch, but this is not the problem of the antenna.
  • Battery connector switch
    For various reasons we install an additional battery connector switch in addition to the installed Redarc. This enables the starter battery to be loaded from solar system, battery loader or the fuel cell. It also allows the truck to be started should the starter battery be flat. The OKA installed (old) Redarc intelligent battery switch is not at all that "intelligent" and doesn't do the job, because it needs starter battery power to manually switch to the second (house) battery for an emergency start. This is technically nonsense. The problem has been solved in the new Redarc switch.
  • Wallas Diesel Stove
    Since 2006 the stove infrequently failed to start due to the lousy electrical connectors of the stove. All critical connectors have been eliminated and the connections are now all hard wired (soldered).
  • Matrix of the transfer case shift lever
    On NT-models the matrix is out of tolerance. That makes it hard or even impossible to correctly adjust the different shift positions of the transfer case lever. The metal plate must be exchanged to correct the issue.
  • Condensed water splash from rear air condition
    One known annoyance of OKAs rear cab air-condition is that it every so often splashes water into the driver cab. This is due to the fact that the condenser unit is mounted exactly level. The condensing water collects at the condenser unit until the driver sharply stops. The unwelcome bath can be avoided by adding a splash-wall in front of the condenser unit which defers the water back into the air-condition housing and down the drain tubes.
  • Splash proof open roof hatches
    Added "splash walls" allow the hatches to be opened 3 cm under all weather conditions. No water can penetrate under any weather condition.
  • Standard door locks reinforced
    The standard door handles are made from plastic. It doesn't need much force to overturn the lock-cylinder with a screwdriver. We added an additional aluminium plate inside the door to overcome this problem as good as possible. Absolute security is not possible.
  • Padlocks on entry doors exchanged
    It takes a professional no time to rip off the "bow" of a good quality padlock (security level 4). We now replaced our padlocks with stronger versions. Abus Titalium 90/50 (security level 8). Absolute security is not possible anyway.


No liability for timeliness, integrity and correctness of this document is accepted.
Last updated: Thursday, 10.01.2019 4:13 PM

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