High Lift Jack Points

If you have front and/or rear bullbars on your Oka, you probably have reinforced hi-lift jacking points installed.

These are very handy for raising the vehicle but are not perfect, so I have added some additional jacking point cutouts on the sides of the bullbars. They can be added even if you don't have the standard jacking points. Bolt-on jacking points are also available from 4WD shops but these are intended for front or rear bullbars, or chassis fitting, and would protrude if fitted to the side of the vehicle, and make it more difficult to attach a jack.

[Note: although I only ever intended to use these new cutouts to provide added stability and safety when using screw or hydraulic jacks, they are actually strong enough to raise wheels off the ground. They should never be used as the sole means of doing this however, and they should always be used in conjunction with other support devices].

Problems with the existing system are:

1) the vertical frame next to the LHS jacking point on the front bullbar fouls the hi-lift jack mechanism making it difficult to fit the jack securely,

The jack fouls this upright.

2) at the back, anything fitted to the rear of the vehicle, like wheel mounting frames and gates, have to be moved aside or opened to get at the jacking points. In our case the rear number plate also covers one jacking point and gets bent in half every time we have to use the jack,

The rear jacking points are hidden and difficult to access.

3) the rear hatch on the bus model can't be opened while the jack is attached, which is a nuisance if you store tools etc. inside,

and, most importantly,

4) the jacking points are about 1/4 of the way across the vehicle so when you want to lift one corner, you are actually lifting a lot of the adjacent corner as well. This makes lifting more difficult and places additional stress on the jack.

A Simple Solution

A simple solution is to cut rectangular holes in the side of the bullbars, as shown in the photos below, to fit the jack in from the side. The holes can be easily cut using a small grinding wheel and I drilled the corners of the holes first to give them more strength. The dimensions for mine were 60 mm x 40 mm (about the same size as the Oka jacking points), but this will depend on the dimensions of the lifting nose on your jack. I didn't make the cutouts big enough for the whole jack nose to enter as that would have weakened the structure. It's sufficient for the nose of the jack to fit in up to its strengthening brace, as is does in the original jacking points.

 New cutouts on the rear bullbar, directly under the diagonal support bar...

...and on the front bullbar next to the step (see note below).

I welded reinforcing bars on the inside of the rear cutouts since they are in the centre of a large flat plate (you can do that from underneath, the bullbar doesn't have to be removed first). There are no reinforcing bars on the front cutouts (originally, they've been added since, see note) since the folded corners of the bullbar are quite close and provide adequate strength.


[Note: since fitting these jack points I've used them several times and the front cutouts tend to bend outwards due to the lifting and pulling effect of the jack. So I've bolted some steel bars to the inside of the cutouts to strengthen them (see pic below). They could be welded on but access to the inside of the front bullbar for welding is a bit more difficult than the rear.]

Support bar bolted inside the front cutout

 Welded reinforcing bars on the inside of the rear bullbars, and drilled corners to prevent tearing.

Now the jack can be operated independently of any other fixtures on the Oka and can lift each corner much more easily. To help the bullbar lift the vehicle, I also slide a piece of 20 mm thick hardwood between the bullbar and body frame, so that some of the lift is transferred directly to the body and the bullbar bolts don't have to bear the full weight.

A piece of hardwood bears some of the lifting force.

Jacking Points In Operation


I found these new cutouts to be surprisingly effective and it's a great help to be able to open the rear hatch (which is where my tools are kept) while the vehicle is raised. Previously, I had to get everything out that I might need for the job before raising the vehicle and inevitably I forgot something critical.

With the original jacking points, it took a lot of effort to raise one wheel off the ground, in fact you can see the bar of the jack deflecting under the strain, even though it is still well within its strength limit. With the new side fixings that task becomes a lot easier and safer (mathematically, about 25-30% less effort required, but slightly more lifting height needed on the jack).


ARB Inconsistency

[Due to their height, Oka's need an extended length 60 inch (152 cm) high lift jack to be effective, such as ARB 204 or 304 see here, about $200. BTW the capacity quoted by ARB is wrong. It's not 1050 kg, it's 2113 kg according to the US manufactures web site here, and they are tested to 3175 kg.

I've raised that inconsistency with ARB and they say it's due to the requirements of the recently modified Australian Standard for jacks in which the capacity of the jack must now be defined by the capability of the handle, not the lifting capacity of the jack.

This doesn't make sense to me since it infers that the handle is only half as strong as it needs to be to use the lifting capacity. The Instruction Manual for the Hi-Lift jack on their US website states that the jack "Meets applicable requirements of ASME/ANSI B30.1 2004 AU/NZS 2693:2007". It's available here.

As a result of my correspondence with ARB, they are now amending their web sites to remove inconsistencies and downgrade their capability to reflect the new requirements. They even offered me my money back (after 4 years!) if I wasn't happy with the new interpretation.]

Side Fixings


Side fixings might also make de-bogging a wheel easier, since you don't need any access under the vehicle. We carry a hub adaptor as well, which allows the hi-lift jack (or a tall screw/hydraulic jack) to be used directly on the wheel hubs for this purpose, but the hub might also be buried so side fixings might be more useable. 


(Note, keep hub adaptors and other such equipment accessible from within the Oka since in a bogging situation you might not be able to gain access to them externally. We once had to help a ute owner who had slid off the Boomfield Track into a drain. His long handled spade was neatly mounted, but completely inaccessible in that situation, underneath his ute).

Safety

As with any jacking method however, never rely on just one jack, leave the wheels on whenever possible or use axle stands in addition to the jack, and chock any unlifted wheels. A spare wheel jammed under the differential can provide additional security.

While you are implementing this mod, it might be wise to check the bullbar bolts for tightness and strength grade. They need to be a fairly high tensile strength. I know, we broke one on the Anne Beadell Highway in 2008 and bullbars are not the easiest of things to remove and replace on the side of the road.

Hand Throttle for the Oka

I know various hand throttles have been described for Oka's before but most seem to need a cable and locking mechanism to keep the cable tight, and you can't easily operate them from outside the vehicle. I wanted something fairly simple for the following purposes:

• Each morning, as I allow the poor old Oka diesel to warm up to a temperature whereby it would actually move the vehicle, I need to set the revs to around 1200,

• I also need to adjust the engine revs from outside the Oka when blowing up the tyres, to keep up with the needs of my engine powered compressor (ex-A/C compressor), and

• although I've never had to do it yet, walking a vehicle down a very steep slope in low ratio is supposedly safer using hand throttle, since it avoids sudden jerks on the throttle.

You actually need quite a lot of force to pull on the top of the throttle pedal to activate it. (For example, to simulate a 5 kg foot on the end of a 20 cm throttle pedal requires a force of 20 kg just 5 cm from the pivot point). So my idea was to put a small rectangular block behind the pedal and twist it sideways against the bulkhead so that it pushes the top of the throttle pedal from the rear.

To do this I fitted a lever to a block of thick nylon from a kitchen chopping board and held it in place by a few brackets. I used nylon so it would slide smoothly across the rear of the pedal, with no wear. The lever pokes out just below the dashboard and has a few indents to set the throttle at a number of speeds. This allows me to set and clear the throttle settings from the driver seat or from the ground outside the door.

The white block of nylon operates the throttle when twisted anti-clockwise.

The nylon block needs shaping to avoid the hydraulic pipes from the brake pedal and needs brackets to hold it into position from whatever fixing holes are convenient. The fixing screws on the lever need to be very tight and their position needs a bit of experimentation to get the lever angles right.

The horizontal bars hold the lever in place but allow it to slide sideways.

The lever needs to be quite strong (hence the steel bar, my initial aluminium bar broke at the indent points).

The lever in it's normal driving tick-over position. The nylon block is not touching the pedal.

[Note: The black pipe below the lever is part of a ducted air conditioning system I have fitted to transfer some warm or cool air to the driver's and passenger's feet. It's tapped into the air duct running across the dashboard. I've also sound-proofed all the metal surfaces in the cabin]

The horizontal bar is spaced away from the bottom ledge of the dashboard and holds the lever in place but allows it to slide across. Holes in the bar were tapped at various locations to allow indent screws to be fitted. The lever needs to be lifted and moved left on to the screws, which match with holes in the lever, so that the speed can be set. This also prevents the lever being accidentally moved while driving. No return spring is required on the hand lever since the throttle pedal has it's own strong spring.

The throttle set at it's maximum position, about 2000 RPM. This position is seldom used but does limit the engine speed.

In its centre position, the engine speed is around 1000-1200 RPM, depending on its temperature, which is just what I wanted.

This mechanism has now been in use for a couple of years quite effectively, except for replacing the original aluminium lever with a steel one after it broke across the indent holes.

Fix the Steering Column Rattle

The steering column in an Oka comprises a telescopic splined shaft and 2 universal joints connecting the steering wheel to the power steering box.


The Oka manuals have good breakdown diagrams (Section 8 of the Parts Manual) and removal descriptions (Section 3 of the Service Manual).

The shaft removed from the Oka. The lower UJ is still on the Steering Box.

If the column rattles over rough roads, it could be the UJ's which are worn or loose, or the sliding joint. The plastic ring inside the column indicator switch assembly can also rattle but that's unlikely to be the real cause.

You can check column wear by holding the lower UJ in your right hand under front of the drivers floor (without the engine running), whilst moving the steering wheel with the left hand. If there's any perceptible movement or clonking, something needs to be done.

If it's the top UJ, the only solution is a new column assembly as the top UJ is part of the shaft body. If it's the lower UJ, that can be replaced independently, but both UJ's will probably be worn by a similar amount. They don't have grease nipples. Note that there are two sizes of lower UJ, one for the original Kirby Bishop steering box and a larger one for the TRW box.

If the sliding joint rattles, it can be fixed fairly simply and at low cost. The shaft doesn't need to be replaced, or even removed.

Although it's a sliding, splined shaft, it spends most of its time working in the same spot and when the paint has worn off the piston shaft, it becomes loose and rattles annoyingly on any rough surface, even though it is still quite safe to use.

I have fixed my rattle by clamping an old urethane spring bush to the piston shaft and then securing that to the main body of the column using a piece of PVC pipe and 2 hose clips. I greased the shaft so it can still slide, but its movement is now heavily damped by the urethane bush and the rattling is eliminated.

The black Urethane Bush clamped to both the piston shaft and body of the column.

To ensure the hose clips cannot catch on anything as the shaft rotates, I surrounded the joint with a larger piece of PVC pipe inserted inside the rubber boot near the floor. A couple of small self tappers will hold this pipe in place.

A piece of PVC Pipe to prevent the clips from catching.

 The bush and PVC pipe need to be split to be fitted around the shaft and column, so in theory, this fix could be done without removing the steering column, just the lower rubber boot would need to be removed. That can best be done by cutting it off with a sharp knife and then gluing it back together afterwards with super-glue. Removing the column is a fiddly job, so I would certainly try this approach first.

The rubber boots, slit up the back to aid reassembly.

If the column has been taken out, now is a good time to check or adjust the steering wheel alignment when wheels are in the straight ahead position, before it is replaced.


Ensure that all the pinch bolts are correctly refitted to the UJs and fully tightened. I put additional lock nuts on top of the Nyloc nuts to ensure they wouldn't work loose.

Note that according to TRW, both UJ's should be refitted with the cross shafts facing the same direction to avoid "cyclic binding" if the UJ's are out of phase:


"Steering column assemblies with more than one universal joint (cardan type) can cause a cyclic binding feel or torque variation at the steering wheel if the u-joints are not in phase with each other".


I assume this to mean that the cross shafts of the UJs should be parallel.


Related Note: I have recently fixed a leak from the input shaft seal on our TRW steering box. See here for details.

Reviving Oka Door Catches

Are your Oka doors difficult to open? Do you have to slam the doors several times to close them properly? Do they fly open unexpectedly on rough tracks?

We've experienced all of the above so I investigated further.


Dust and grit are the first suspects for making the door catches recalcitrant, followed by wear and tear. Fortunately the door catches are industrial strength and are quite easily fixed.

Dust and Grit

The door is held shut by a 2 position ratchet and pawl system. (See Pic 1 centre). Grit and dust can dry out the grease between moving surfaces increasing frictional forces. This makes closing and opening difficult since the plates won't slide smoothly and the pawl won't always drop into the ratchet, despite the strong spring. A full overhaul requires the removal of the door mechanism from inside the door, see the Power Door Lock blog post for details on how to remove the catches (you might need to log-in to the Oka Owners Group website).

Pic 1. The Ratchet and Pawl System.

Degreasing and cleaning out all the gritty sludge from the mechanism is the best solution followed by a full re-oiling of rotating components and re-greasing of the sliding plates. Also ensure that the ratchet to pawl spring is not stretched and is correctly fitted. It should be quite difficult to remove as it's quite strong.

Dust can enter via the rectangular cut out in the side of the door through which the catch protrudes, particularly the depressed rivet area, (see pic below), which allows free access for dust into the door cavity. The answer is a layer of thin closed cell foam strip stuck around the opening before the catch is refitted. The foam will compress during assembly and form a good dust barrier.

Pic 2. Dust can enter here

Wear and Tear

The next problem is wear and tear on the barrel which transfers the tension from the external latch to the internal ratchet and pawl system. Normally the ratchet plate is in line with the pawl, but when the barrel shaft or sliding surfaces are worn, under extreme shock (eg from a bump on a rough track or the door being slammed shut), the plate can move out of line. The pawl can then jump out of the ratchet and the door flies open, or won't close securely. (See Pic 3).

Pic 3. A worn barrel allows the ratchet to jump free from the pawl.

Wear on the barrel creates a gap between the door catch and the barrel spacer (see Pic 4). This is more difficult to fix since the plates at either end are sweated on and peened over to prevent movement.

Pic 4. The gap caused by wear on the barrel.

A simple solution is to wind one or 2 turns of fine galvanised fencing wire around the outside of the barrel to take up the wear gap. (See Pic 5) This reduces the inward movement of the internal ratchet plate and prevents the pawl from jumping out of the ratchet.

A large circlip would be a better solution but would be difficult to insert. By contrast, fencing wire is quick and easy to fit.

Pic 5. Wires can fill the gap.

You don't even have to remove the catch to make this fix. It can be done from outside. It might not last for ever but it's cheap, quick and effective, and easy to replace. It can also be done on the rear tailgate catches on the bus model.

The last(?) wear and tear problem is the latch plate which hits the striker. This is often worn and won't hold the striker rod tightly and securely.

Pic 6. This latch plate (from a tailgate) has been heavily repaired and is badly worn.

The only easy solution to this problem is to lay some weld on the worn "C" shape (it should be a nice "U" shape) and file it down so it fits and turns on the striker rod smoothly. It's not a quick job but will make a lot of difference to door closing and retention.

If the striker rod itself is worn, as mine were, you could wrap a layer of steel shim around it to pack out the wear. This worked surprisingly well for several years. Alternatively, weld could be laid on the worn part of the rod and filed/ground round.

Finally, ensure that the striker plates on the door frames are adjusted properly (so that the door closes tightly without slamming and doesn't rattle) and the Allen headed screws done up tight so the plate can't move. BTW, never remove all the Allen screws at the same time. The threaded lock plate inside the door frame can drop down, never to be seen again.

And why not grease the door hinges while you're at it? I'll bet that doesn't get done very often because I've found it's necessary to remove the door stay strut on some doors to allow the door to open far enough to access the grease nipples.

Replacing the Oka Springs

Replacing the springs on an Oka is a straightforward but heavy and time consuming job.

Springs are heavy (60-70 kgs each) and unwieldy things to move about and locate with any precision and safety. 

A Simple Spring Trolley

I built a small but sturdy trolley to make it easier to manoeuvre them around the workshop and locate the springs under the Oka. It was constructed out of scrap timber and fitted with some old skateboard wheels recovered from long abandoned children's play equipment (the skateboards, not the children) . The sets of wheels were modified to rotate through 90º so the trolley can be moved sideways when under the vehicle, to locate the spring eye in the mounting bracket.

It needs to be a "U" shape to go round the end of the axle and wide enough to avoid the brake callipers (and steering rods on the front). Blocks can be added as necessary to rise or lower the height of the spring as it is being located under the vehicle.

Start with the spring inverted.
(It will still need to be manoeuvred over the brake calliper).

Carefully turn the spring (they are unstable things).

We found it was easier (and safer) to locate the spring under the Oka whilst mounted upside down on the trolley so it will clear exhaust pipes, bodywork, spring mounting brackets etc, and then invert it when in approximately the right place. Be very careful not to crush fingers when manoeuvring the spring!

Now it can be turned upright and moved into position.

Obviously the Oka needs to be securely supported before removal of the old springs. In my case I built a set of very strong chassis stands made from steel girders to support the Oka 1 meter off the ground, which is the height you need to remove an unsprung spring.

We used High Lift jack (60 inch model) to lift the Oka while manoeuvring the stand under the chassis. In theory you could raise both sides at once to enable removal of both springs simultaneously. However, the vehicle does not feel secure with 2 wheels off the ground and with the axle is no longer constrained, it can move or rotate, so it's much safer to do one side at a time.

Heavy Duty Chassis Stand

Whilst replacing the springs, I also upgraded the suspension bolts to 20mm (up from the standard 16mm size) plus urethane bushes. I got these in a kit from Peter Wright, see http://okaownersgroup.info/tiki-index.php?page_ref_id=416 (you'll need to log-in to the Oka Ownwers Group website).

It does need some serious drilling of existing chassis holes and the holes in the spring shackle plates, plus welding of support plates, but the end result looks very strong and maybe will reduce the number of suspension failures we have had on our 0utback trips (3 spring eyes and 2 bolts broken so far, and it's not fun repairing these on remote tracks).

20mm Bolts. Note the lead-in on the end of the bolts to make alignment easier.

If there is significant lateral wear on the shackles, chassis plates or spring mounts to allow the spring eyes to move sideways, they will clonk when turning. Steel thrust plates can be inserted to take up the gap, usually about 1 to 2 mm thick but not so thick that all movement is prevented. The spring eyes must be able to rotate in their mounts.

A thrust plate located on a hanging shackle

Fitting the hanging shackle plates is not too difficult, but aligning the fixed eye end of the springs requires manoeuvring of the spring. This can be done by putting a piece of timber under it so the centre bolt doesn't drop into any holes on the axle and then levering the spring along the top of the axle. Once the bolts are in, a more difficult job is to get the spring and axle aligned, because with the spring unsprung, its centre bolt will be no way near its axle mounting hole.

In the workshop I placed 2, 25mm round bars under the rails of an axle stand to act as rollers on a concrete floor, and lowered the axle on to it (the axle weight is not sufficient to cause damage to the axle stand). Using levers, I could then move the axle to and fro a small amount until the centre bolt and its mounting hole lined up. 


Compressing the spring with a separate jack may also help with alignment. With the vehicle jacked up on one side, there may be considerable lateral misalignment as well, due to one side of the vehicle being higher than the other. The answer is to lift the other side a bit to level the vehicle, but be careful, 3 wheels on the ground is fairly stable, 2 wheels is not. A lot of levering will still be necessary and a breaker bar is very useful for this.

Even when greased and carefully aligned, the bolts may still be a tight fit in the spring bushes (if you are using urethane bushes) and mounting plates. Hammering is seldom effective because the bolt "bounces" in the bush and it can also damage the threads. A simple pusher can be made by using a large G-clamp and putting a socket over the thread end of the bolt (and removing the grease nipple from the head end or using a socket to protect it) and tightening the clamp until sufficient thread protrudes to allow the nut to be fitted. The nut can then be tightened up to pull the rest of the bolt into position. Peter Wright's 20 mm bolts have a lead-in protrusion with a removable tapered cap to assist with alignment. This works well.

With urethane bushes, it's important not to over-tighten the shackle bolts since the bushes can be crushed and the shackle plates can bind on the spring or chassis. This will put additional strain on the spring eyes and lead to premature failure. Tighten the nuts to seat the bolt heads fully and then back them off until its washer just won't turn. That's tight enough, the nuts are only there to keep the bolts and spring components firmly in place. Being Nyloc nuts they shouldn't work loose, but if you are concerned about that, holes can be drilled in the ends of the bolts and "R" pins fitted to retain the nuts.

With the new larger 20 mm bolts fitted, the top shackle bolt on the rear of the drivers side front spring fouled the exhaust pipe after passing through the chassis, see pic below. In fact I had to remove the front pipe to even fit the bolt. So after it was installed, I lopped off the lead-in end on the bolt with an angle grinder and pressed a 1 cm depression in the pipe around the area of the bolt head to ensure that there would be no contact when the engine rocks under load. Even the previous 16 mm bolts been touching the exhaust pipe and caused a wear mark. I also rotated the muffler (which has off-centre entry and exit flanges) so as to direct the front pipe as as far from the suspension bolt as possible.

The chassis bolt fouls the exhaust pipe.

We got new rear springs made by Industrial Springs in Adelaide and we had an extra 3rd leaf fitted to provide support to the spring eyes. The fronts weren't too bad (Industrial Springs had renovated them a few years ago with new 1st and 2nd leaves) so we just had them beefed up with an additional 3rd leaf fitted and the springs were reset.

Raised Roof Development (under construction)

We constructed a raised roof for the Oka, as an alternative to a poptop, which will give us sufficient head room to walk about and additional storage which is not available in a pop-top design.

Overall height was initially a concern on bush tracks, but the design height is no more than a bus model fitted with a roof rack and loaded with equipment, and we wanted room to move inside. In 6 years of travel, height has only been a concern on a couple of occasions, where low bridges have stopped us (and would probably have stopped other Oka's too). It does get attacked by overhanging branches but width is usually more of a concern on narrow tracks than height. Solar panels have been subsequently fitted across the cab, the frames of which provide substantial protection against errant branches.

The roof is built from a 25 mm square aluminium tube frame covered with aluminium sheeting. The roof beams were bent 3º is 3 places using a home made pipe bender to give the roof a slight curve.

The whole structure was pop-riveted together using an air-powered riveter (there are over a 1000 3/16th (4.7mm) pop rivets and doing this by hand would have required Popeye sized forearms). The over-cab section is more of an enclosed roof-rack for storage of lightweight, infrequently used items such as ropes, fanbelts, hoses, awning sides and walls, cold weather gear etc. I subsequently fitted a solar panel frame across the outside, over the cab.

The main roof frame was built on a wooden space frame with the exact dimensions of the Oka roof line. This made construction a lot easier than working 2 1/2m up in the air.

The frame is substantially complete, now for a test fitting.

The frame is surprisingly strong, but the leading edges and rear panels were reinforced the to withstand the inevitable attack by tree branches.

With the nose cone assembled it was time for a final fitting of the frame before the lining and skin were fitted. The shape is partly for asthetics and partly as an attempt at improving aerodynamics.

The roof was lined with 5mm CoreFlute, a sort of corrugated plastic sheeting normally used for sign boards, with edges fixed using plastic wall framing mouldings and double sided sticky tape to hold it in place during construction. When complete the roof lining sheets are held in place between the plastic mouldings and the original Oka roof. The CoreFlute was covered with FrontRunner headlining material (also called WonderWall, from Spotlight), stuck on with spray adhesive.

Lighting, fans and vents were built in to the frame and wired up before the lining was installed. The exhaust grille for the fridge was also built into the side of the roof. The frame was insulated with 25 mm thick GreenStuf polyester fibre to avoid the dangers of fibreglass or polystyrene.

All the materials were tested for flammability before use. CoreFlute, WonderWall and Greenstuff do burn, but they don't flare up and are largely self extinguishing.

The outer aluminium skin was attached to the frame with Sikaflex 252 using all the recommended cleaning and priming instructions. The sheets overlap by 25mm from the rear to avoid leaks and were strapped on for 24 hours for the adhesive to cure.

The edge curves for the top sheets were made by bending them over a length of 150 mm PVC pipe clamped to the edge of a work bench before fitting. The curved front side sections were first made using templates of brown paper to get the shape and size right before cutting the aluminium. It's surprising how different curved, angled sheets look when laid out flat.

The seams were sealed using Sikabond Pro and touched up with white paint.

Completed roof assembly on its wooden spaceframe model, parked outside while the Oka was prepared to receive it.

Cutting out the existing Oka roof sheet proved to be quite easy with a jigsaw, and the support bars cut with an angle grinder. However, I was surprised just how heavy the removed sheet of roofing steel was.

The cut out is in from the edges by about 400mm so we can use the remaining roof area as the bottom of overhead cupboards.

Fitting the Roof. The was an exciting day when all the planning and construction work came together. After a couple of minor hiccups, the roof fitted on with no major dramas. I made a frame to suspend the roof from the shed beams as it was lowered on to the Oka.

Before fitting the roof, I weighed it on its wooden space frame using a simple lever-arm balance, like this. I used a full 4 l paint can (about 4 kg) as the counter-balance weight and adjusted the pivot point until the roof was just lifting at one end and measured the pivot point distances. Using these I calculated the roof weight. I repeated the process at the other end and added the results together. The weight was approx. 36 kg.

The roof is attached to the Oka using 3mm aluminium strips Sikaflexed to the roof and bolted to the Oka using the existing roof rack bolts. This maintains the sealed structure of the roof down the sides of the Oka to minimise leakage or dust ingress. A bead of polystyrene rope was inserted all round the lower edge of the roof to keep out draughts and insects.

The roof is further mechanically secured via 4 bulkheads forming the walls of the internal roof cupboards, as above. The 3 mm aluminium bulkheads are bolted to the roof beams at the top and to the original roof support bars at the bottom. In 6 years of travel the roof has never moved or leaked.

Final fitting of the roof presented a challenge as I knew the shed door would not be tall enough to get the Oka out with the new roof on. We needed another 300mm and some lateral thought was required. In the end we cut out the front of the shed roof and jacked it up so it looks a bit like a chinese temple. But we are now be able to drive in and out with about 200mm to spare.

This is the roof after it's first fitting. It looks exactly as the originally planned design.

Internal views of roof before construction of the interior fittings. The inside of the roof looks quite swish and has plenty of headroom for us (1.85m). There will be plenty of storage space around the inside of the new roof.

The completed roof on its first outing, showing the side plates which hold it down.

The internal fit out will be described in subsequent articles.