Mercedes-Benz Forum banner

1 - 20 of 28 Posts

·
Registered
Joined
·
9,491 Posts
Discussion Starter #1
I thought that I may have already posted this one, but it did not show up in a search, so here it is.

Maybe for the second time.


It looks to be in Prime shape, with about 56K kilometers on the clock.
 

Attachments

·
Registered
Joined
·
439 Posts
I can’t help myself I have to stereotype and make fun of the Dutch….my Dutch friends would be hurt if I didn’t….



This thing is just begging to be turned into a caravan, RV or overland vehicle (politically correct term for an RV based on a Unimog). …………………………….. I mean a Dutch Unimog has to be a camper, it is some sort of national rule, and a Dutch 1550l REALLY needs to be a camper, sorry overland vehicle…..



Th explanation…for those of you who have not lived in Europe, in summer time the Dutch leave there small home country in mass and caravan/RV across Germany, France and beyond…anytime you are out driving around on the autobahn, in the summer, and see a camper/trailer there is at least a 75% chance it has the distinctive yellow license plates of the Netherland….
 

·
Registered
Joined
·
9,491 Posts
Discussion Starter #8
Well, that is hard to say, but it looks like there is also a bit of a dimple in the same place on the right side. Just bonking the corners on a tree will do that, or any number of other things that were contacted.

Now, if you drive around with the front hinge pivots locked in, it is possible to bend the fender / cowl area. Locking the corners in sends the stresses from the frame flex into the fender panel, and it can crumple. That damage usually shows up to the rear, and lower, near the diagonal seam line of the front fender.

Here are a couple of shots of the creases that result from having the hinges locked.

For the Dutch DOKA I'd guess that they are random bonks.
 

Attachments

·
Registered
Joined
·
9,491 Posts
Discussion Starter #9 (Edited)
As I ponder this, and with both sides showing damage in the same area, maybe 'Random Bonks' are not the issue...

There was a very similar dent that showed up on my truck.

I didn't do it, and it appeared after the cab was tilted while the head gasket was replaced. I asked the shop about it, but they had no idea...and I didn't push it.

Since it is similar to what shows on the Dutch DOKA, and since it certainly happened while in the shop's care, I wonder if it is a type of damage that can happen while 'over-tilting' the cab or something.

It seems like if you hit the bumper or other pieces by letting the cab go too far, there would be some damage to the paint to give evidence to the impact.

My paint was fine, and the paint on the Dutch UNIMOG looks to be intact as well.

I wonder if this sort of damage could result from the cab coming to a hard stop while tilting it forward. There would be no paint damage, but maybe the shock of the stop would dimple the upper corners. I don't know, but the damage on my truck looks similar, and I know the cab was tilted during that time period.

I suppose it could also happen during the lowering process, if you bounced it or set it down hard.

I've tilted the cab on the Grey one without damage, and that truck has the ride-along cab tilting jack. The green DOKA did not have that system, so the shop would have been using a chain fall or a hoist of some type...I don't know.

The Dutch DOKA shows the tilting equipment in place.

The fact that they are both DOKAs might be a factor, or not.

Mine was only dented on the one side. I never thought that the damage was a result of tilting the cab until just now, but I wonder?
 

Attachments

·
Registered
Joined
·
224 Posts
Mine came with the same bonks! I could never find a “how the heck” reason...!!

I’ve tilted my cab to replace my 352 with a 366 and monitored the front end... it could not find a way.

Interesting mystery!
 

·
Registered
Joined
·
9,491 Posts
Discussion Starter #11
You know, it could be a DOKA thing - the hinges are the same as on the single cabs, but there is quite a bit more weight hanging off of them, and the increased leverage on those pins must be considerable.

Maybe the key is to never let the DOKA cab 'get loose', and shock load the system. When I can't sleep some night, I'll have to paw through the DOKA files to see if these dimples are a thing or not.

I don't see the damage on your truck, but maybe the stripes help hide it, or the panels were straight when the photos were taken...


In Greece, was it, west of Larisa ?
 

Attachments

·
Registered
Joined
·
224 Posts
Not sure when, but noticed after I removed the stripes. Those pics, what I bought and what I received we’re a bit different 😉

My original concern was the integrity of the front, and approached raising the cab carefully to the point of exposing the lower joint to check for rust and separation but everything was/is fine and solid.
 

·
Registered
Joined
·
1,171 Posts
Mine came with the same dimple as your green Doka but on the drivers side. Always thought they just hit it.......I've had my cab up a half dozen times and seemed very stable and not too stressed. I have been slow and never really pushed pass the ram. The Dokas don't seem to open/lift as high/angled as the regular cabs so may be it is that they have been pushed too far as Tructor stated.
Chas
 

·
Registered
Joined
·
9,491 Posts
Discussion Starter #14
Looks like the same sort of a dimple.

I think it is looking like a 'DOKA thing'.

What was Ian Fleming's line from Goldfinger ?

" Once is happenstance.Twice is coincidence.Three times is enemy action ."

In this case, three times looks to be a structural weakness, or at least a proclivity for getting dimples in the same spot due to something or other.
 

Attachments

·
Registered
Joined
·
9,491 Posts
Discussion Starter #16 (Edited)
No stone, or dimple, left unturned in seeking the answer.

The accumulation of knowledge can be brutal.

Seriously, though, it does seem like we have stumbled upon a problem that occasionally afflicts the DOKAs, and which would seem to involve lifting the cab.

The damage looks consistent, and there is no outward damage, like scrapes or impact scars.....which leads me to think they bend in that area because the sheetmetal can't handle the stress.

It is similar to the creases in the cowl which can happen when you drive with the tilting hinges locked, but smaller and (maybe) specific to the DOKAs.

I could see it happening during the lowering of the cab. If you were coming down on a hydraulic strut, and closed the valve quickly, it might put enough stress on the cab to dimple it. The onboard jacking system is not centered, it is on the right rear, which could be a factor, but the dimples slow up on either side, or both, so who knows?

The factory ride-along system is a jack-up / jack-down system, so you can't shut the valve down quickly, causing an abrupt stop. A number of guys have used hydraulic jacks with a release valve from engine hoists or other applications, and it would be possible to have a fast lowering and a quick stop with those. I think it might be something else, however.

You do have to stop the process at one point to insure that the steering linkage is aligned before you lower all the way down. Also, it is possible to think you have the steering shaft engaged when you actually don't. If you continue to lower the cab, I could see a bending moment occurring possibly, because the weight of the cab is pushing the cab down, and the hydraulic strut is relaxed, so it is not supporting the cab, but the steering shaft is 'straight arming' the UNIMOG in the cowl area, which might cause the damage.

It is best to have two people, at least, when lowering the cab, so the steering shaft can be guided by one person as the other manipulates the jack, the hoist, or whatever hillbilly device is being employed. The device does not matter, they could all put the cab in a position where it wants to go all of the way down, but it is being held up by a steel shaft that is much closer to the front corner of the cab, than it is to the mass of the cab, where all of the weight is pressing down.

This situation would be much worse on a DOKA, because of all of the additional weight from the cowl on back.

I'm just speculating here, trying to find an explanation, but I have had the steering shaft stop the process by not being properly aligned, so I know that can happen.. I have always been without that second person when tilting the cab, it seems.

I don't know, but it seems possible.

Something is afoot, Watson.

Something Evil.
 

Attachments

·
Registered
Joined
·
9,491 Posts
Discussion Starter #19 (Edited)
I don't know - the sample size is so small at this point. It could be that the hole cut into the sheetmetal at that point for the turn indicator is a factor. More on this below.

The 'high' marker lights are the original, regular lights. The low turn indicators came along later, when the high horsepower U2100-U2400 UNIMOGs came along with the raised cabs.

They lowered the turn indicators to stay within the German regulations. The lower turn indicators are the same lamp unit, but they have a thicker gasket that they fit into. This gasket is made to compensate for the different curvature of the corner sheetmetal lower down on the body. It was a good solution so that they did not have to redesign the lamp. The fat gasket soaks up the difference in the body contour, and the lamp sits more proud of the sheetmetal, possibly to also provide clearance between the lamp and the interior structure....

I was told the 'sheetmetal contour' explanation for the fat gasket in Germany, and I accept that, but the more I look at the clearance in the hole, I think moving the lamp out and away from the interior structure has to be an equal part of it.


In looking at some photos of the two cab types, it looks like the cut-outs for the higher lights might well be a contributory factor here. The hole wraps the corner, which is not great structurally, but the fender panel is sort of on its own up at the top corner - there isn't much in the way of supporting structure.

There is a vertical strut there, which anchors the fender and the grill opening vertically, but it ends in space and does not tie back to the firewall. If it did, I don't think these dimples would be an issue.

Now, the lowered lights just happen to come to rest in a spot where they are well supported by the interior structure. There is a diagonal beam that runs from the firewall to the lower corner were the hinge pivot is located. The rest of the fender is along for the ride.

I'd be surprised if the UNIMOGs with the lowered lights have a dimpling problem, but I can see why the trucks with the Higher lights might be prone to damage in that area. If that wrap around cut-out weakens that corner of the fender...I would not be surprised.

Some photos to ponder -
 

Attachments

·
Registered
Joined
·
9,491 Posts
Discussion Starter #20 (Edited)
Some more.

The diagonal beam and the rest of it looks to be essentially unchanged on the (White) UHN cab.

Maybe if the Nose was just a bit 'deeper', and the hood a little steeper, they could have tied the vertical front corner strut back to the cowl, running a small beam above the engine intake and the cowl vent for the interior.

This would have tied it together into a nice box, and although I don't know how much attention they would have paid to crumple zones on these things, they could have had both, a nice box structure which was also engineered to function as a crumple zone.

They could also just 'slide' the two cowl vents lower, down the diagonal beam, to buy a little room for a beam. You would not need much, maybe an inch and a half above the vents or so.
 

Attachments

1 - 20 of 28 Posts
About this Discussion
27 Replies
9 Participants
abockelie
Mercedes-Benz Forum
BenzWorld.org forum is one of the largest Mercedes-Benz owner websites offering the most comprehensive collection of Mercedes-Benz information anywhere in the world. The site includes MB Forums, News, Galleries, Publications, Classifieds, Events and much more!
Full Forum Listing
Top