Merkabah: MB 2626 AK 6x6 tipper to expedition truck conversion
- Thread starter pairospam
- Start date
Hello there:
Yes... it is an eternal ongoing project. Unfortunately I have many restrictions, time restrictions mostly, and I haven't had done big progresses.
I am a little stuck with electrics and pneumatics, but I am still working on it.
Many greetings, Neil, Josst, MadBkr, Sitec and all the crew.
Pairoa
Yes... it is an eternal ongoing project. Unfortunately I have many restrictions, time restrictions mostly, and I haven't had done big progresses.
I am a little stuck with electrics and pneumatics, but I am still working on it.
Many greetings, Neil, Josst, MadBkr, Sitec and all the crew.
Pairoa
Hi everybody:
Well, as some of you know, the work on the truck has never ceased though it has been quite slow, especially the last few months.
Just to illustrate what has been done lately, according or not with the plans, and some of the problems I have had to face during this times, I will show a few pictures trying not to be too boring.
Basically, with the engine already running, I needed to complete a few labors before having a functional truck: electrics, pneumatics, drive train, brakes, air conditioning, interior lining of the cabin and some others.
The Merkabah is an amateur project and, as such, it depends on my free time to go on. As a quite busy guy I try my best to make progresses, sometimes working on a specific item because of its relative easiness or availability of spares, not following a precise schedule or pattern, sometimes doing random tasks depending on the availability of time. And, sometimes, the original plans and ideas have changed.
Well… that’s why it’s been eight years since the beginning of the adventure.
For example, following the advice of a good friend with a similar device, I decided to install the manifolds for the CTIS and the air suspension in the cabin, instead of putting them on the outside. The only place available was, of course, in the central console, and they both fitted by the millimeter.
It was a good decision, though it was not easy to arrange the tubing and the electric wires and stuff in such a tiny space.
Among other things, I put air piloted valves to purge the air tanks. They would become very difficult to reach after completing the build of the truck. All the air tanks got such a valve connected to a 3/2 valve in the cabin, and thus it would be an easy routine to purge the air tanks every time you start the engine and let the pressure build up.
When the long gear shifting tube was installed, after rebuilding and installing the shift lever, I realized that it was still too long, so I had to heat it up, again, and bend it a little more, which I didn’t like at all. After a while I realized that the shortening was excessive but I preferred to play with the terminals and not to touch the tube again.
At some moment a couple of special tiny and pretty powerful batteries came to my hands and the nicely modified battery tray became oversized, again. Still not sure what to do about it.
You can also see that I had installed a double chamber air dryer to manage the pressurized air. Both CTIS and the air suspension valves needed dry and pretty clean air to work properly.
Air conditioning was a story on its own, and still is a running one. To install the compressor, I had to build a pretty tough support, custom tailored, so it could fit in the incredibly tight space between the engine and the frame rail. It was hard, guys.
Well, as some of you know, the work on the truck has never ceased though it has been quite slow, especially the last few months.
Just to illustrate what has been done lately, according or not with the plans, and some of the problems I have had to face during this times, I will show a few pictures trying not to be too boring.
Basically, with the engine already running, I needed to complete a few labors before having a functional truck: electrics, pneumatics, drive train, brakes, air conditioning, interior lining of the cabin and some others.
The Merkabah is an amateur project and, as such, it depends on my free time to go on. As a quite busy guy I try my best to make progresses, sometimes working on a specific item because of its relative easiness or availability of spares, not following a precise schedule or pattern, sometimes doing random tasks depending on the availability of time. And, sometimes, the original plans and ideas have changed.
Well… that’s why it’s been eight years since the beginning of the adventure.
For example, following the advice of a good friend with a similar device, I decided to install the manifolds for the CTIS and the air suspension in the cabin, instead of putting them on the outside. The only place available was, of course, in the central console, and they both fitted by the millimeter.
It was a good decision, though it was not easy to arrange the tubing and the electric wires and stuff in such a tiny space.
Among other things, I put air piloted valves to purge the air tanks. They would become very difficult to reach after completing the build of the truck. All the air tanks got such a valve connected to a 3/2 valve in the cabin, and thus it would be an easy routine to purge the air tanks every time you start the engine and let the pressure build up.
When the long gear shifting tube was installed, after rebuilding and installing the shift lever, I realized that it was still too long, so I had to heat it up, again, and bend it a little more, which I didn’t like at all. After a while I realized that the shortening was excessive but I preferred to play with the terminals and not to touch the tube again.
At some moment a couple of special tiny and pretty powerful batteries came to my hands and the nicely modified battery tray became oversized, again. Still not sure what to do about it.
You can also see that I had installed a double chamber air dryer to manage the pressurized air. Both CTIS and the air suspension valves needed dry and pretty clean air to work properly.
Air conditioning was a story on its own, and still is a running one. To install the compressor, I had to build a pretty tough support, custom tailored, so it could fit in the incredibly tight space between the engine and the frame rail. It was hard, guys.
Maths didn’t work when referring to the amount of electric power the truck would need to run all the systems, and the alternator decided to quit before being put at test. He died most abruptly and had to be replaced for a bigger and more powerful one.
The engine had been running for short periods since the beginning of times on its own, but then the electric system was connected and many circuits did not work properly, as expected, of course.
Despite having tagged it all and checked many times when rebuilding the cable harnesses and connectors, I had to check them all, even opening the already loomed ones. I found many errors and wrong connections, but slowly corrected them and finally made them work properly.
Putting all the wires in place, original and new, was a big piece of work, and it made every corner of the frame look pretty crowded.
The central console, the passthrough of all the new electric and pneumatic systems going in and out of the cabin, was especially susceptible of suffering chaos. The alarm alone had so, so, so many cables itself.
I got a few terminal strips to put some order, and in the beginning it was okay, but as the number of connections grew up the place became messy again.
As a detail, just one in a million, the ignition barrel lock died just when I was in the middle of many important tests. eBay provided an original one, of course, but I had to wait for it as with many other little but important pieces.
The engine had been running for short periods since the beginning of times on its own, but then the electric system was connected and many circuits did not work properly, as expected, of course.
Despite having tagged it all and checked many times when rebuilding the cable harnesses and connectors, I had to check them all, even opening the already loomed ones. I found many errors and wrong connections, but slowly corrected them and finally made them work properly.
Putting all the wires in place, original and new, was a big piece of work, and it made every corner of the frame look pretty crowded.
The central console, the passthrough of all the new electric and pneumatic systems going in and out of the cabin, was especially susceptible of suffering chaos. The alarm alone had so, so, so many cables itself.
I got a few terminal strips to put some order, and in the beginning it was okay, but as the number of connections grew up the place became messy again.
As a detail, just one in a million, the ignition barrel lock died just when I was in the middle of many important tests. eBay provided an original one, of course, but I had to wait for it as with many other little but important pieces.
The instrument panel for the central console underwent many changes in its design as it had to match to the growing content of the console.
In the end, the final layout seemed to be the best, though the stereo and the speakers had just few millimeters of clearance.
You can imagine how bad I wanted to make the truck run, though there was always something to slow down the progresses. Anyway, I took the old seats of the Mitsubishi Montero and started to modify the bases to install them on the cabin, but the work to be done was so big that I just grabbed the old base and the original seat of the truck and bolted them in place. And that was it… at least for that moment.
Until then, the diesel fuel for running the engine was provided by a 20-liter plastic canister placed on the gear box. The 520-liter tank needed completion to accommodate the original fuel sender.
The tank of the venerable Spare truck was the donor of the ad hoc piece as I was too lazy to work on the tank myself and have to re-paint it.
Once installed, glued and bolted, the big tank was put in place and the fuel system connected.
Had to pour in 80 liters of diesel to get the level of the fuel sender tip, though.
The new double-shock arrangement was in conflict with the drag link, and so I had to take the new drag link, heat it up and curve it just the right amount to allow it to have the necessary clearance to move freely, with no conflict with the tires neither.
In the end, the final layout seemed to be the best, though the stereo and the speakers had just few millimeters of clearance.
You can imagine how bad I wanted to make the truck run, though there was always something to slow down the progresses. Anyway, I took the old seats of the Mitsubishi Montero and started to modify the bases to install them on the cabin, but the work to be done was so big that I just grabbed the old base and the original seat of the truck and bolted them in place. And that was it… at least for that moment.
Until then, the diesel fuel for running the engine was provided by a 20-liter plastic canister placed on the gear box. The 520-liter tank needed completion to accommodate the original fuel sender.
The tank of the venerable Spare truck was the donor of the ad hoc piece as I was too lazy to work on the tank myself and have to re-paint it.
Once installed, glued and bolted, the big tank was put in place and the fuel system connected.
Had to pour in 80 liters of diesel to get the level of the fuel sender tip, though.
The new double-shock arrangement was in conflict with the drag link, and so I had to take the new drag link, heat it up and curve it just the right amount to allow it to have the necessary clearance to move freely, with no conflict with the tires neither.
At that point, the truck looked pretty good and almost ready to run, right? Just imagine the doors are there.
I aligned the wheels and, theoretically and practically, the Merkabah could steer without mechanical problems, if only she could run.
The CTIS and the air suspension system needed both an independent air management system apart from the double air dryer/cleaner, and the elements were set along with the components of the air conditioning in the front of the engine, under the cabin, pretty at hand.
Once all the components of the pressurized air system of the truck were, supposedly, ready, I connected the compressor to the air governor and thus to the other many elements.
Among other issues, the pressure did not raise and kept under the threshold. I needed 100 psi at least to make it all work.
To make a long story short, there were some wrong connections between the air source and the valves, and some valves were wrongly set, and I had to check them all, one by one. I discovered big mistakes and some minor ones, nothing really tremendous though time consuming.
There was quite a bunch of air leaks, some of them I could fix with tightening or adding some Teflon tape, but some had to change the connectors and fittings. Some I could not stop completely at the first nor at the second try.
I aligned the wheels and, theoretically and practically, the Merkabah could steer without mechanical problems, if only she could run.
The CTIS and the air suspension system needed both an independent air management system apart from the double air dryer/cleaner, and the elements were set along with the components of the air conditioning in the front of the engine, under the cabin, pretty at hand.
Once all the components of the pressurized air system of the truck were, supposedly, ready, I connected the compressor to the air governor and thus to the other many elements.
Among other issues, the pressure did not raise and kept under the threshold. I needed 100 psi at least to make it all work.
To make a long story short, there were some wrong connections between the air source and the valves, and some valves were wrongly set, and I had to check them all, one by one. I discovered big mistakes and some minor ones, nothing really tremendous though time consuming.
There was quite a bunch of air leaks, some of them I could fix with tightening or adding some Teflon tape, but some had to change the connectors and fittings. Some I could not stop completely at the first nor at the second try.
In the meantime, I had realized, when installing the gear shifting tube, that the gearshift shaft on the gearbox was jammed. Hoped that applying air pressure to the circuit would make it unblock… but it did not.
In short, I had to open the gearbox to reach the mechanism and the jammed pin to unblock it manually. Fortunately, the lateral cover was thought to be removed if needed, and it ended up being a good thing as it helped me to clean the box from ancient oil/tar that would have been pretty difficult to do without opening the box.
After dealing with the gearbox, I put the truck on the trestles in order to check the drive train freely. Unfortunately, the air valve that commanded the shifting of the low and high range and the reverse gear refused to work because of age and neglect.
Not being able to fix it, I made quite an extensive search and found the proper spare locally. The new valve arrived a few days later.
In short, I had to open the gearbox to reach the mechanism and the jammed pin to unblock it manually. Fortunately, the lateral cover was thought to be removed if needed, and it ended up being a good thing as it helped me to clean the box from ancient oil/tar that would have been pretty difficult to do without opening the box.
After dealing with the gearbox, I put the truck on the trestles in order to check the drive train freely. Unfortunately, the air valve that commanded the shifting of the low and high range and the reverse gear refused to work because of age and neglect.
Not being able to fix it, I made quite an extensive search and found the proper spare locally. The new valve arrived a few days later.
At the same time, I finally made the air pressure build up and remain stable. The new governor and the double air dryer worked perfectly and cut precisely at 115 psi, as expected.
After checking and changing a few connections, filling and purging the clutch circuit, the gear shifting started to work as it should, from the gear shift lever in the cabin to the last of the gears of the box.
Everybody at the workshop was happy though quite concerned looking at the truck with the big wheels spinning in the air. What if one of the trestles give up, Pairoa? They shouted.
Of course they were right, as the truck still had no brakes. I had tried to purge the brake cylinder in many ways, many times, unsuccessfully. It was pretty frustrating, though this particular model is well known for being difficult to make the dual brakes work.
Checking this and that I got the hydraulic circuits cleaned, washed, refilled, washed again and refilled many times. The cylinder was taken out and purged on the bench and then reinstalled, followed the procedures on MB manuals… but nothing worked.
I had also problems with the differential locks. Some worked, some not. I disassembled them and found that time and neglect had also made a lot of damage there, and the mechanisms were not in their best shape.
Fortunately, with some love and care, I made them work at last and all of them, longitudinal and transverse, were fully functional after a while.
I got this photogram from the video of the final test. You can easily imagine the six wheels spinning slowly backwards, all at the same pace, don’t you?
After checking and changing a few connections, filling and purging the clutch circuit, the gear shifting started to work as it should, from the gear shift lever in the cabin to the last of the gears of the box.
Everybody at the workshop was happy though quite concerned looking at the truck with the big wheels spinning in the air. What if one of the trestles give up, Pairoa? They shouted.
Of course they were right, as the truck still had no brakes. I had tried to purge the brake cylinder in many ways, many times, unsuccessfully. It was pretty frustrating, though this particular model is well known for being difficult to make the dual brakes work.
Checking this and that I got the hydraulic circuits cleaned, washed, refilled, washed again and refilled many times. The cylinder was taken out and purged on the bench and then reinstalled, followed the procedures on MB manuals… but nothing worked.
I had also problems with the differential locks. Some worked, some not. I disassembled them and found that time and neglect had also made a lot of damage there, and the mechanisms were not in their best shape.
Fortunately, with some love and care, I made them work at last and all of them, longitudinal and transverse, were fully functional after a while.
I got this photogram from the video of the final test. You can easily imagine the six wheels spinning slowly backwards, all at the same pace, don’t you?
The brake issue, despite efforts and geniality, was (is) far from being solved. The cylinder, a brand new one, was disassembled and found that the rubber valves were softer than they would be. A new cylinder, the best European brand and make, was ordered hoping it would be the solution.
On other front, some problems arouse, like the finding of a leak on the seal of the tip of the crankshaft. Ops. Also, a ring on at least one of the cylinders blocked do to the unopposed working of the engine since so long. Those were big problems that should be addressed once the truck could move by itself.
Meanwhile, I continued with the completion of the other items. I got a nice splitter from 24V to 12V to feed the 12V circuits of the Merkabah. The first failed on its own after a couple of minutes. The second one I blew up by confusing the output terminals, ops. So, the third one was put in place in the dashboard, hoping it would endure. Until now it does.
Wanted to test the air suspension control system, but when connecting the proper dedicated air tank the pressure dropped and a few leaks were clearly identifiable. Great expectations but greater rust.
Waiting for the tank to be repaired I made some new connections and the system worked the way it was supposed to do, giving easy and complete control, from the comfort of the cabin, of the softness/hardness of the suspension. It would also allow to compensate mild to moderate uneven terrain when parking.
Following was the setting of the CTIS. I installed and connected the control box on the console panel, checked, and it worked pretty well.
Next, I began to build the supports for the rotary valves to be installed on the wheel hubs and to make the connections for them to get the air from the lines that come out from the CTIS manifold and get the tires inflated and deflated at will. Ah… sounds good.
This is where I am at the moment, with very little time to work on the truck but with the same will and the best mood, waiting for the brake cylinder to arrive from some place to be able to move the truck on its own power.
Hope you like it and send the best vibes. They are always welcome.
Greetings from Chile.
On other front, some problems arouse, like the finding of a leak on the seal of the tip of the crankshaft. Ops. Also, a ring on at least one of the cylinders blocked do to the unopposed working of the engine since so long. Those were big problems that should be addressed once the truck could move by itself.
Meanwhile, I continued with the completion of the other items. I got a nice splitter from 24V to 12V to feed the 12V circuits of the Merkabah. The first failed on its own after a couple of minutes. The second one I blew up by confusing the output terminals, ops. So, the third one was put in place in the dashboard, hoping it would endure. Until now it does.
Wanted to test the air suspension control system, but when connecting the proper dedicated air tank the pressure dropped and a few leaks were clearly identifiable. Great expectations but greater rust.
Waiting for the tank to be repaired I made some new connections and the system worked the way it was supposed to do, giving easy and complete control, from the comfort of the cabin, of the softness/hardness of the suspension. It would also allow to compensate mild to moderate uneven terrain when parking.
Following was the setting of the CTIS. I installed and connected the control box on the console panel, checked, and it worked pretty well.
Next, I began to build the supports for the rotary valves to be installed on the wheel hubs and to make the connections for them to get the air from the lines that come out from the CTIS manifold and get the tires inflated and deflated at will. Ah… sounds good.
This is where I am at the moment, with very little time to work on the truck but with the same will and the best mood, waiting for the brake cylinder to arrive from some place to be able to move the truck on its own power.
Hope you like it and send the best vibes. They are always welcome.
Greetings from Chile.
Sitec
Adventurer
Great to hear an update!! Glad it's still progressing!! It's looking fantastic, and great detail too!! Just keep going as the truck side of things is so close now. I'd leave the battery tray as standard, as if you ever need to change batteries when somewhere more remote, they would only carry standard large batteries. (big ask starting that V8 on those two gel batteries too). Re the rope air con belt.... love it. Saves carrying a selection of belts!!! 
Keep at it fella. It'll be worth it!
Keep at it fella. It'll be worth it!