Merkabah: MB 2626 AK 6x6 tipper to expedition truck conversion

#16
After many interrupted hours of work the block was completely naked. When we could we took it and the camshafts from Spare and from the Merkabah to a very reputed machine-shop in Santiago to take off the camshaft bearings and replace them with new ones. Nothing could be done to save the old camshafts so I had to buy a new one and took it to them also to complete the assembling.

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I worked a little on the right footstep taken from the cabin of the Merkabah, trying to remove any sign of rust and old paint and flattening out the seriously bruised metal sheet. The results were less satisfying than expected, but given the circumstances the job was judged good enough.

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By that time, I met the Casales, a couple of brothers that ran their MB truck for the second time in the Chilean-Argentinian version of the Dakar rally. Coincidentally we shared some common history, relatives and friends, and the passion for steel, grease and camping. I took from them seven used and very rusted rims from who knows wich european army truck; well, not so rusted and perfectly rescueable rims. They had used similar rims twice in the Dakar and did not have any trouble with them.

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I bought also six of their GoodYear 14.00R20 tyres to initially stand up the Merkabah and later on I would pick two more as spares. For the rally they imported a full container of such tyres and they were selling at a very convenient price those they did not use.

The short bed of the Mitsubishi had room for only four of the massive tyres at a time so I had to go twice to Santiago to pick them up. I could not resist to put them aside the truck when I brang them to the countryside to keep them in a shed. The normal tyres looked like toy wheels. I remember also picking the rims and taking them to a sandblasting shop near San Felipe a few days later.

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#19
Yes, Iain_U1250... it is the only way to go.

A very big decision had been postponed until that moment: the colour of the Merkabah. I made a flash trip to the paint-shop to take many samples and drank many cups of tea while discussing the issue with my wife, Carmen. We have very similar tastes so the decision was, of course, all hers. The Merkabah would travel the whole world dressed in SY-5263-P.

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There were many problems with the sand blasting but finally they delivered the rims and the rings after a couple of weeks. The work had to be completed by hand but it was not that bad in the end.

I primed the rims and the rings at the workshop, in a very tight place. Priming only took me three days. I used the old little compressor that lasted only a few hours of non-stop work before dying in the middle of the painting session. Had to buy a bigger one and after many problems with it I finished to paint the rims at 2:00 A.M. in one session.

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When the rims were ready I made the tyres mounted on them and rushed to put them in the Merkabah. I put all the six wheels, heavy as hell, in the afternoon. The look of the truck changed dramatically and for the first time the Merkabah got its “all-terrain” allure, and I loved it, but I ended up exhausted.

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I put also a lot of energy and dedicated a lot of time to the design of the Box, and particularly to define the measures and materials of all the components. The interior layout was actually not very innovative, with the dining place in front and the fresh water reserves underneath, the kitchen and ward cabinets in the middle, bathroom and shower separated and facing each other, with the main bedroom in the back, over a big utility space. The measures were the longest and widest they could be in allowance to the Chilean laws and for that given wheelbase, 640 x 250 mm. The height could not surpass 380 cm or I would not be able to go through the oldest tunnels and bridges.

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#20
I'm jealous of the amount of space you have. We spent a lot of time sorting out our interior, even going to the point of building it out of plywood and spending a whole day in it. I'm not sure how far you are with building your camper box, but looking at your design sketches, we have a few suggestions based on our experience.

What we found in many campers is that they are very claustrophobic. Cupbaords at head height, and the lack of big windows makes even the biggest ones feel tiny. We were fortunate to be able to sit in two big Unicats, a GXV, a massive custom MAN 6x6, Earthcruisers and ATW campers and all the caravans and winnebago type RV's at the camping shows we could find. Sadly, in nearly all of them we both felt very crammed in, and were worried about living inside our little truck for extended periods of bad weather.

We decided to only have one full height cupboard, and limited the overhead lockers at the front and rear only. We built a raised section in the middle of the ceiling to create a feeling of extra space and height. The lack of things at your eye line makes it feel big. We have sat down with four people inside the back and chatted for almost three hours. Trish and I sat on the bed, and our visitors on the seats. At the end, our visitors remarked how big it felt inside, despite it being only 3.4x2.1x1.9m
 
#21
Iain:

I have read your thread and I know that everything you have done so far you have thought about at least three times before doing it. My deepest respect.

Never be jealous of what another guy might have; one way or another it will cost him more, sooner or later.

As in every build, the layout is a compromise between your will and your needs. I know it is a little bulky but we always carry a lot of stuff and we plan to live in the truck for some months while we build our definitive house, so we need storage space, a lot of storage space.

Anyway, even if the design is complete, after countless revisitings, I want to put together the living cabin and to build a cardboard mockup of the interior in order to be completely sure of what I have designed before I place the first screw.

When you are with friends, though, having a good time and a good chat on some quiet interesting subject, you can be in the smallest toilet cabinet for hours and you would never mind. Routine and steadiness... that's the killer.

More to come later.


Cheers.


Pairoa
 
#22
Hi Pairoa, I have just caught up on your build thread : http://www.allrad-lkw-gemeinschaft.de/phpBB3/viewtopic.php?f=33&t=26452&start=360.
The amount of work and care you are putting in is astounding, great work!
You have a ton of space to work with, probably more than you think. I am sure you have played with many interior layouts. My MB 917 cabin is also 2.4m wide. There is plenty of room for a large fridge freezer then a walkway then seating for four at a table with seating facing front and back. I think turning your dinette would give you more usable space. (don't forget the pass through is not in the center of the vehicle)
Something common in long distance trucks is the fiberglass "topper" on the cab roof. I rarely seen it used on expedition trucks. It provides good aerodynamics for the vehicle, provides a lot of interior storage space, and allows a far larger connection between the cab and cabin. It will force you to get those wheels off the roof and into a better location!
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Have you given any consideration to hydraulic leveling jacks? Now is the time although you are probably getting tired of drilling the frame.
I would look at trying to find the space to get the first two exit steps inside the vehicle so that your exterior ladder will be shorter or even reduced to a single step.
Is your gray water tank inside the insulated envelope of the cabin? It does not need to be. In sub zero temps we allow it to dump on the ground. We also have a valve operable from the cab so we can dump the gray water tank while driving (off road)
I am concerned with the weight of your battery bank. I understand you avoiding propane because of difficulties finding it in different countries. I would reconsider your all electric plan. Propane in addition to electrics gives you redundancy. Propane can be got in most countries and it is easy to carry a very long term supply (we carry 2 75l tanks between the frame rails, enough to run the fridge freezer and cook with for many months)
155Ahr is not a lot for an 8d battery . Are they deep cycle or starter? Made in China? Starter batteries will not last as house batteries.
Going with a set of quality deep cycle batteries such as Lifeline (255Ahr made in USA) or Rolls (325 Ahr made in Canada) will save space, weight and frustration. Sourcing comparables in Chile is another matter.
One good thing about AGM batteries is they will work underwater so you don't have to have the watertight battery box you were going to build.
I am just throwing some thoughts of things that work for me now that you are having to get the cabin design down. I am in awe of your project, please take my ideas as random thoughts to improve your vehicle. If nothing else they may spark some new ideas of your own. It is easy to get in a design "rut"
As for your back, I understand completely, you feel you will never stand upright again. It will pass, rest and anti-inflammatories, its not brain surgery!
Cheers, Joe
 
#23
Hi Joe:

Sorry but I don't know how to manage the QUOTE thing. Anyway, thanks for your comments and ideas, mostly appreciated.

Let's see:

I personally do not like the fiberglass toppers as they make the trucks look like grocery delivery trucks, even though they are pretty useful. Neither I am concerned about aerodynamics with a 13 ton, 6x6, 260 hp all-terrain workhorse.

The spares on the roof of the cabin were just a modelling exercise; the cabin does not hold those 300 kg, but the screen fits anything.

Every hydraulic gadget has been removed and the PTO flew away as well. I have conceived the design to rely on pneumatics instead. Cleaner and easier to repair and service.

The ladder will be hidden under the Box in the classic pull-out configuration. There is enough space for it and, anyway, the diesel tank does not allow for another idea.

The gray tanks will hang from the Box, outside, also with remote valves.

The last word on the energy issue hasn't been spoken yet. The batteries are indeed chinese, deep cycle, work underwater, heavy as hell (53 kg each), and the most important...for free! The bank will have eight of them. You are right, getting the right batteries is difficult and very, very expensive.

I am still considering to have a 15 kg propane/methane bottle and a portable two fire stove with it in the storage area, just in case. There is no more place left between the frame rails for anything.

My back is okay now, well... 80% of the regular okay, and I am back at work on the Merkabah.

Thanks again.


Pairoa
 
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#24
There would be a box for the batteries and another box for the generator, both of them bolted to the frame of the truck on he driver’s side. On the other side would go the stretched diesel tank. The Box would rest on four pivoting mounts bolted to an integrated subframe/base panel of the box. Utility boxes for spares, tools, gray and black water would hang from the Box on the rear sides and above the rear wheels.
On the back, there was initially a rack for two spare wheels or one motorcycle with a pivoting arm connected to an electric winch. Nothing spectacular neither there. The design changed eventually to allow storage of one spare and the bike, but in the meantime I played a lot with alternative layouts including the improbable two spare wheels over the cabin.

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The guys from the machinery shop gave us a thousand excuses, but they did not finish their job on time and they delivered the block directly at the workshop in San Felipe a couple of weeks later, on their own expenses. The heavy piece of steel, chemically washed and carefully wrapped, would have to wait until the end of the holydays before the beginning of the reassembling

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Carmen and I went finally on vacations, far south. Before the departure I had another vision and saw the truck that would be the donor of the snorkel for the Merkabah. The search for the kit was fruitless until then. We found the truck, just like in my vision, 1200 km from home, on the big island of Chiloé. After some strange moves I took it from the cabin and kept it on the back of the Terrano for the rest of the trip.

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The picture shows the farthest you can go south by 4x4 on Chiloé, near a place called Cucao. Very nice.

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On arrival I found the starter and the alternator full serviced. They were the first pieces to be serviced and painted.

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#25
Eduardo and I ordered all the spares and gaskets needed to overhaul the engine, the clutch and the air compressor. There were many problems with some big spares that made me go to Santiago more than once, as happened with the press of the clutch, the water pump and the inertial flywheel. The last made the guys of the Mercedes official dealer go crazy, but they finally found the right one. The codes had changed more than once in thirty years.

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The lonely truck at the cattle waited patiently, but some leaks in the bogie showed up and slowly grew, stressing the need to hurry things up.

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Finally, on April, I removed the plastic film that covered the block since the new camshaft bearings were adjusted, and the pitiless rust showed up on the sleeves. “Never fear!”- Eduardo shouted - “A little #400 sand paper, kerosene and gasoline mixture and the thing can be easily fixed!”. And then Pairoa began to sand vigorously but carefully the sleeves under the inquisitive eye of the mechanic chief. It was not a killing task, but it required a precise technique and, as everything in this project, it took time, a lot of time.

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When the sleeves were polished and ready I put the block upside down to put the new stuff in. I proceeded by installing the cam followers on the block, the real first concrete action of reassembling the engine of the Merkabah. What a feeling! Then put back in place the camshaft with the aid of Eduardo. The new shaft, with its pointed and sharp cams, fitted and turned perfectly as expected.

At every step Eduardo taught me to be patient and to pay a lot of attention when putting on every piece like the flat bearings of the crankshaft. He put the first one and I put the rest of them, excited like a little boy with his brand new toy.

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I washed the crankshaft carefully but there was some paint dust adhered to it despite the efforts to cover everything when painting. Pairoa, with #600 sand paper and the old pantyhose sanding method worked a little more until every crankpin shone in the 100 watt lamp light.

It was late when we hung the crankshaft from the winch and after a few maneuvers and a growing feeling of desperation we put it in the block. Ah!

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A few days later the lower main bearing caps along with the bearing shells were put at their place. Oh, extraordinary feeling when making the crankshaft turn so smoothly!
 
#26
The momentary ecstasies lasted only a little moment because the turn arrived for the pistons to get prepared. Eduardo told me that the only things they needed were some love, dedication and careful grinding. I resigned to the idea and began to work on them with tons of patience. It was very hard to clean the pistons and leave them without any trace of carbon making no damage to the fragile aluminum, but in the end it was very satisfying to see them shining, clean and fresh. Well, almost. The pistons were kept in their original position thanks to the order maintained throughout the process and thanks to the photographic records; all marks disappeared after the cleaning.

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Some hours of labor and a few issues later (lost connecting-rod bearings and a little damage to the edge of one of the sleeves) the pistons with their proper new rings were back in the block. After the installation of every piston followed some tightening, torque and turning test of the crankshaft to make sure that everything worked. Oh, extraordinary feeling of smooth crankshaft spinning each time!

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There was no extractor socket for the injectors at hand and we could not find one elsewhere, for a reasonable price at least, so made my own extractor with a long 22 mm. socket and the power grinder. To remove the 16 injectors it was necessary a lot of work, even if the new tool performed brilliantly. The injectors all looked pretty bad, but I had learned that sometimes it does not matter how ugly the components might look at first sight, they can still be in good shape. Dirty they were, but remember that the truck came from Talca, many kilometers away, and it even did not consume too much. Hmmm…

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All the injectors were cleaned up and sent to a diesel injection laboratory in a near town, actually the best in its class in Chile, the same that had to repair and calibrate the diesel pump. They had to test and select ten of the injectors in best shape, repair and service them.

Once the injectors were out I could not escape from the job of cleaning and adjusting the valves and the cylinders heads. I sighed and with a big forced smile I prepared myself for a task I wondered to be worse than cleaning the pistons, and I was not wrong.

The valves were dirty but were easily cleaned with light metal brushing. It took me quit a bit to clean and adjust the 16 valves at Eduardo's standard; truly annoying, as I supposed earlier on. On the picture it cannot be appreciated but I had been on the same move for more than two hours that day, and was beginning to think on quitting. The valves were OK, though, and it was worth the bothering.

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As well, every cylinder head took me almost one hour to clean the way I wanted it to be done. When I finished the first row of cylinder heads I felt very happy, but as I began with the sixth head I realized that the metal borders of the coolant circuit was ugly corroded, with an actual risk of leaking because the gasket would not cover the defect. Bad. The last head had the same problem too.

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I examined the cylinder heads from Spare and selected the best ones. Fortunately two of them were in good condition, enough to be used even if they showed some corrosion damage. Surely the owners of both trucks did not use coolant but some uglish water.
 
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#30
One head per cylinder, that is a great idea. Looks like you have a lot of patience, what did you use to clean the pistons without damaging them?
Yes, it is quiet practical; you can change anything you want from the plain cranckshaft bearings to the sleeves without even taking the engine out if you like (or if you have no choice)

I do have patience, at least I had at that time. I used #600 sand paper, kerosene and gasoline 50/50 mixture and a few hours of carefull grinding.

For cleaning the grooves I used a broken piston ring to eliminate the hard carbon and then some stripes of a firm cloth with the solvents mixture.

A close up.

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Cheers.


Pairoa