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U1450L DOKA
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Discussion Starter · #1 ·
OK, this is an attempt to look at and illustrate the situation when confronted with tilting the DOKA cab in order to remove the engine.
The chore is basically the same as the procedure with a regular cab, it is just that the length and additional weight of the DOKA cab complicates things a little.

The crux of the issue is raising the cab enough to get the engine out, and also accounting for the engine hoist. The requirement is to get the cab out of the way enough so that there enough vertical space to get the engine up and over the frame rails, while keeping it clear of the shift plate structure.

If the Engine has the Claas overdrive on it, or the PTO drive housing, then things will be more complicated yet.

Once the cab is tilted enough to create this clearance, then whether it is a Regular Cab or a DOKA, it doesn't matter - the excess length of the DOKA is up and far out of the way. Now, getting it up all of the way is another issue, but more on that later.

How much tilt ? Well, there is only one answer : Full Tilt Boogie. The maximum tilt takes the front contour of the fender within an inch of the bumper. The raised cab is a little different , as the cab has been raised 100mm. so the pivots are that much higher to begin with, but when tilted to the maximum, the gap to the bumper is also pretty tight.

Some photos shoeing the Full Tilt Boogie.
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U1450L DOKA
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Discussion Starter · #2 ·
OK, so both the regular and the DOKA have to be stood on their nose to the same degree. The Regular Cab is equipped to do that with the factory jack system, but the DOKA is not. It also has the option of being equipped with the hydraulic jack, but at full extension, it does not come anywhere near the necessary elevation. It is pretty simple - the Doka has the jack at the right rear corner, whereas the Regular cab has it under the driver's door, so the full extension of the ram can't possibly lift the DOKA as far.

What sort of angles are we talking about ? Well, I took a protractor and held it up to various photos on the computer screen, in order to get some idea of the relative angles that the two cabs achieve when raised by the factory jack.

I'm not pretending that these numbers are super accurate, but I think that they are a reasonable approximation.
The DOKA reaches an angle of about 25° - this is consistent between the diagram and the photos. The Regular cab more than doubles that - 55
 

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Discussion Starter · #3 ·
55° to 65°, depending on which photo or diagram is measured. This is a huge difference, obviously.
Have a look.

When I raised my DOKA cab, I took the jack to the maximum, and the protractor held up against the photo of my truck shows 25°. The Red Lines are at that angle, the Blue lines are at the angle of the Regular Cab at Full Tilt (~ 65°).

You can see the challenge facing DOKA owners, as the last photo shows how much further my truck would have to pivot in order to get the Engine out. (Bottom of my cab to the Blue line.)

(Yes, I actually found a diagram showing the Extended cab DOKA tilted in my files...You'll note that the jack is not at the extreme rear of the extended cab, but probably at the same sopt as it would be on a regular cab DOKA, hence the angle measures in at 25° for that one as well.)

Again, all the angles are approximate...


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Discussion Starter · #4 ·
To put it in perspective, these photos from Schüssler show an Ex-Military DOKA in their shop, tilted higher than any other DOKA that I have photos of.
However, I don't think it has not achieved the necessary Full Tilt Boogie (Uncle Louie song) position that would allow the Engine to come out. The fender is not close enough to the bumper - that lowered turn indicator has another couple of inches to go, I believe. Because it has a raised cab, it might squeak out, but I think it would have to go to where the yellow cab is. Ponder that if you will.
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Discussion Starter · #5 ·
Some more Full Tilt shots of regular cabs. Note that the Camo cab looks to have been pushed past Full Tilt Boogie limits and into the bumper, which left a dent. (Next page - I have to find my grabs.)
Also, the White over Orange cab is at a steeper angle than FTB it seems, which was facilitated by removing the front bumper.
Next to last photo shows a raised cab White UNIMOG in what I'd say is the FTB position, and which is at a noticeably steeper angle than the Schüssler DOKA. (More like the Yellow raised cab angle.)






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Discussion Starter · #6 ·
Some More -
The Operation of transplanting the OM366L(A) Brazilian Bus Engine into Dr. Mark's Blue U1300L shows a couple of details. Kai is leading the charge, manning the engine hoist, while Roberto is shown in position on the belay line. In the
shot through the grill, you'll note that the head is off of the OM352. I think they may have taken it off to prospect for problems, seeing if it could be repaired in place, or for clearance while removing it. I'd guess the former, but I don't know - I can't remember if the OM366L(A) was purchased and ready to go at that point or not.

In that same shot, you can see that the Cab is not jacked to FTB position, but when Kai is wheeling the engine out, and in other photos, it has been cranked up further.
Another detail seen in other photos is that the Yellow strut that safeties the body is made to run from the top of the spring perch to the body when the cab is fully tilted - this just reinforces the notion that the cab has to be to the maximum angle to get the engine out.

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Discussion Starter · #7 ·
There is more to cover :
The hinges and pins at the front.
The Rings at the rear.
Jacking vs Hoisting from overhead.
Using a team for the lift, and a theoretical outline for the process.
And, other stuff I can't remember at the moment...

In order to knock something else off of the list before I call it a day, I'll jump to the lifting rings.


Previously, I agreed with Scott that the jacking system was for tilting, and the rings where for setting up a safety. However, in the Builder's Book, I came across information that indicated that they were provided as an alternate way to lift the cab.
So, there use is pretty obvious, as far as that goes.

I would suggest that before using them that you take a close look at the panel they are attached to, inside and out, and the floor underneath. Rust can be anywhere, but that fill-in panel at the bottom of the back wall seems to get a good dose of it. That panel is fitted because the back wall of the regular cab is used, and the floor slopes up to that line for that application. On a DOKA, that panel is added to close the box up, as the floor is flat.

Some DOKAs don't have any rings - possibly because that panel has been repaired, or the DOKAs are 'Home-Made' from a regular cab, and they just didn't do the whole job.

Anyway, the rings are dangerous to worthless if they are not 100% sound.

They do come in handy as anchors for safety lines, of course.

They must be stronger than they look, as UNIDAN in Australia, and others, have used them and the pivot pins to lift the the DOKA cab and fly it around,without issues, it would appear.


I'll include a shot of the lifting ring in place on the current UHE regular cab. It looks like a step up. (next)

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Discussion Starter · #9 ·
Please excuse the typos - my proofreading has failed me. I see the missing 'is', the 'not' where it does not belong, and other things...
It bugs me, but I expect the sun will come up tomorrow.
- Typo King
 

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Discussion Starter · #11 ·
This is a photo of the strut that can be installed across the grill opening to help stabilize the fenders. This photo is from
the MEREX building closest to the River Murg - the ex-Ice Cream Factory part of the complex.

Building such a strut is probably a good idea.....That said, I think that this is the only photo I have that shows one installed. The other thing is that if you have a winch on the front, then one like this won't work unless you remove the winch.
I think you could use the same concept and move the strut uphill a bit, over the edge, so it bridged the gap at the front edge of the hood panel, rather than on the 'vertical' grill area. That should buy you more winch clearance, depending on which monster you have mounted up front.Yellow lines represent crackpot theories.

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Discussion Starter · #14 ·
The front pivot pins . These must also be in excellent shape for safely tilting the cab, but unfortunately they live in a spot that is prone to rust damage.

The front clip is a curious arrangement, and I don't think it is a great design, but that is just from me staring at it.

The pivot pins live at the front, at the bottom of an angled sheetmetal beam on each side. These beams are welded to the firewall, and they are essentially a dead end. There is a short vertical piece of angle, but it is only the fender skin that forms the majority of the structure. (Area-wise)
I don't know if the engineers were going for a crush zone with this design or what, but it is what it is, and nearly 50 years later it remains about the same.

One problem with the design, and the one that affects the integrity of the pivot pins, is that it is a rust trap. Briefly, there is a slot that exists between the beam and the fender skin. The beam, as mentioned, slopes down from the firewall to the pivot pin, so any moisture or debris trapped in the slot tends to follow the downward path towards the pin.
There are small drains at the bottom of the beam, but any debris or mud that enters the slot will tend to clog them. Depending on how and where the UNIMOG is used, leaves, twigs, mud, gravel and so on, can form a layer of moisture-holding crud that is the ideal breeding ground for rust damage.

Any rust that takes hold can rot the corner away, and some of the damaged pins look like you could grab them and twist them off of the truck.

The rust damage can be substantial before it is detected - the slot is buried under the washer bottle on the right side of the truck, and hidden behind a wad of electrical and air lines that are arching up towards the firewall on the left. To inspect the slots and clean them out and flush them with a garden hose requires some disassembly of the the air cleaner, the washer tank and so on.....
The photos should tell the story.
 

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...it would be sweet if someone had this level of photographic detail concerning the tilting of a ROUND CAB DOKA. Yes, the info exists somewhere in the archives but it's not al in one spot and glosses over several important items like the tilt bracket details and fitting.

Just a thought...
 

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Discussion Starter · #17 ·
I’ve had -10 degrees here, but only at night.

I can try to pull together something similar for the 416 (etc),
but owners of them and guys that make the tilting brackets will have to chime in to fill in what are probably considerable gaps in my information.
I know that I have enough to make a start.
 

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Discussion Starter · #18 ·
This shot shows how the washer tank effectively puts that slot out of sight and out of mind. Add the Air Cleaner assembly and put the cab on a chassis with a hydraulic tank hugging the fender and you just don't see it to worry about it.
The Left side isn't quite as buried, but the Radiator and Fan assembly, along with the air lines and so on, do obscure it pretty well.
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Discussion Starter · #20 ·
Chad - I have to revise my earlier theory. Looking at this extended DOKA, it is clear that the illustration come from a Mercedes-Benz Publication. The images bleeding through show an MB Trac, which is unlikely to appear in a Ziegler hand book or a Fireman's Handbook.
The fact that it is on a page with two other UNIMOGs with the model numbers specified nails it down.

It doesn't mean that Ziegler and the other body builders don't have a manual spelling out the tilting procedure, just that Mercedes might have a little bit too.

Now, where did the image come from - just something I pulled from the internet, or could it be from something I have in a box somewhere ? Probably the former, but maybe I can find out which manual it is from by going through those files.



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