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
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
- 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
- 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
- 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
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
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
- 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
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
- 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
- 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.
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!
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.
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.
Thursday, 10.01.2019 4:13 PM
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