FLU419 SEE HMMH HME Owners group

Hummerdave said:

Hi everybody.. I finally have another engine sitting in the frame and getting stuff hooked up to it. I thought I took good pics of the details but I did not get any of the dang suppressors and the polarity breaker wiring.. would someone have pics or details on the wires coming and going to that.. I have looked all thru the manuals and this item is just not covered anywhere..
thanks,
Dave

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i have a redneck pinout of the terminals. give me some time to dig.

skippytdi said:

i have a redneck pinout of the terminals. give me some time to dig.

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no i don't. i'll check it at the next light.

skippytdi said:

What do you consider on the road range rpm?
are you also going to tell us that the see is unstable and dangerous at full convoy speeds?
from what sources are you basing these "quirks" of the mog pto?

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hi SkippyTDI. Not sure what I might have said for you to get combative. Always just trying to help. Max engine rpm on the OM-352 is typically wide open on the governor and that rpm varies somewhat vehicle by vehicle. Typical is 2800 rpm, or whatever seems a safe speed. Earlier OM-352s, pre-SEE, were lower, 2600 or 2700 rpm.

Define 'convoy speed' ?

Do I think a short truck with the mass of a loader on front, and a backhoe on the back gets unstable at highway speed? Why yes, I do.

Max engine rpm with Hi Cap hydraulics (PTO) engaged: page 49, Operators Manual 9-3401, "IMPORTANT (their caps and bold) Always disengage the hydraulic pump before driving the Unimog or before operating the engine above 2175 rpm. Damage to the pump could result". Why would you want to keep the hydraulics engaged on the road??

No combativeness. Theres a freightliner demo video on youtube that shows just how unstable the see is at full speed. Somehow i don't think that a vehicle that was difficult/dangerous/unstable to drive at its contractually rated top speed would have had such a long run with the military. Its lack of popularity, i feel, is its european style maintenance and operation that was disliked by americans used to american engineering/operational styles.

In any given time, considering the choices of gearing, the only time i could see anyone winding the snot out of a big diesel is if gearing has been maxed out. PTO operation at full convoy speed absolutely not but it seems as if the general rumor keeps floating around that the pto is not supposed to be engaged while the wheels are turning in any way shape or form.
Let me ask you, if there an RPM limit to a standard unimog with front pto shaft pto?

tennmogger said:

hi SkippyTDI. Not sure what I might have said for you to get combative. Always just trying to help. Max engine rpm on the OM-352 is typically wide open on the governor and that rpm varies somewhat vehicle by vehicle. Typical is 2800 rpm, or whatever seems a safe speed. Earlier OM-352s, pre-SEE, were lower, 2600 or 2700 rpm.

Define 'convoy speed' ?

Do I think a short truck with the mass of a loader on front, and a backhoe on the back gets unstable at highway speed? Why yes, I do.

Max engine rpm with Hi Cap hydraulics (PTO) engaged: page 49, Operators Manual 9-3401, "IMPORTANT (their caps and bold) Always disengage the hydraulic pump before driving the Unimog or before operating the engine above 2175 rpm. Damage to the pump could result". Why would you want to keep the hydraulics engaged on the road??

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skippytdi said:

No combativeness. Theres a freightliner demo video on youtube that shows just how unstable the see is at full speed. Somehow i don't think that a vehicle that was difficult/dangerous/unstable to drive at its contractually rated top speed would have had such a long run with the military. Its lack of popularity, i feel, is its european style maintenance and operation that was disliked by americans used to american engineering/operational styles.

In any given time, considering the choices of gearing, the only time i could see anyone winding the snot out of a big diesel is if gearing has been maxed out. PTO operation at full convoy speed absolutely not but it seems as if the general rumor keeps floating around that the pto is not supposed to be engaged while the wheels are turning in any way shape or form.
Let me ask you, if there an RPM limit to a standard unimog with front pto shaft pto?

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---
Hi, I agree completely about safety issue of a loaded SEE at full speed. Perhaps the important issue here is 'where' the SEE is driven hard and fast. In the field with the military is a whole different situation than on highway with soccer moms darting in and out LOL.

Regarding the max engine rpm with PTO, it's the hi-cap hydraulic system that limits the speed (therefore the reason to turn it off). The rear/high capacity pump was designed for maximum flow at a 'work' rpm, like 1800. If run faster than that, fluid heating and cooling become issues. The front hydraulic system (run off the engine) is designed to handle full engine speed, so has no speed limit.

Of course the SEE does not have the 'normal' 540/1000 mechanical PTO and shafts. Unimog 406's with that normal PTO are not speed limited but why leave then in gear. Actually there are at least four PTO assemblies available on a standard 406, the 540/1000 off the side of the transmission, the high speed PTO off the bottom (on which the hydraulic pump runs), and two different high speed PTO's that can be run off the cascade box ahead of the transmission.

Lots of the Unimog fans drive their 406 or 416 Unimogs cross country. They will set the engine on the peg (2800 or even turned up to 3000) and drive for hours. Those OM-352 engines are remarkable, and the SEE transmission has evolved to the point it can handle high speeds, too. Think about doing that with, say, a Deuce and a half with a multi-fuel. Chances are good the engine will come apart in a few hundred miles. Oops, maybe I should not have said that

Bob

skippytdi said:

No combativeness. Theres a freightliner demo video on youtube that shows just how unstable the see is at full speed. Somehow i don't think that a vehicle that was difficult/dangerous/unstable to drive at its contractually rated top speed would have had such a long run with the military. Its lack of popularity, i feel, is its european style maintenance and operation that was disliked by americans used to american engineering/operational styles.

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There might be something to what you say. It's like the Metric issue:

- Once you've used Metric, it makes a whole lot more sense, AND makes life easier, than working with Imperial measurements (like are you kidding 1/16's and 1/32's!?)

- But the inertia of the "old method" doesn't want to budge. We're a stubborn lot.

not 100 percent on the b- terminal brown wire.
also please note that this is how i found it wired. no symptoms of
not functioning properly but the ' b- to ground near starter' was initially found to
be a wee bit toasty..
i wouldn't mind bypassing all these extra's, i just want a good ol' alternator with two
or three wires connected to it.
if tennmogger would learn to use a camera perhaps we can get some ' back of
a civi mog' alternator pics and a civi diagram...
my phone is not processing the drag uploaded file attachment
so please refer to the following post..

Hummerdave said:

Hi everybody.. I finally have another engine sitting in the frame and getting stuff hooked up to it. I thought I took good pics of the details but I did not get any of the dang suppressors and the polarity breaker wiring.. would someone have pics or details on the wires coming and going to that.. I have looked all thru the manuals and this item is just not covered anywhere..
thanks,
Dave

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Thanks for the diagram! Now I have to try and figure out which wire is which since yours has colored wires and I have the good ol' mil wiring that is all black with tiny numbers stamped on... oh well..
Dave

So a quick update & question - I drive the 'Mog on the highway at a wide open 46mph with no problems.
I did notice after a drive through the country, that after sitting for a day or two the engine acts like it is not getting fuel. Before it would start after tapping the starter, now it will spin and spin without starting. A shot of ether gets it to start up running slow then straightens out and runs regular. It will start right up after this for hours after starting. Seems like fuel starvation.

Any thoughts on this one?

Hummerdave said:

Thanks for the diagram! Now I have to try and figure out which wire is which since yours has colored wires and I have the good ol' mil wiring that is all black with tiny numbers stamped on... oh well..
Dave

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Don't get discouraged, hummerdave:

- NOTHING is ever easy.

That's just the automatic given.

flu419 said:

So a quick update & question - I drive the 'Mog on the highway at a wide open 46mph with no problems.
I did notice after a drive through the country, that after sitting for a day or two the engine acts like it is not getting fuel. Before it would start after tapping the starter, now it will spin and spin without starting. A shot of ether gets it to start up running slow then straightens out and runs regular. It will start right up after this for hours after starting. Seems like fuel starvation.

Any thoughts on this one?

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That is classic symptom of air ingress into a fuel line connection. It's a slow air leak 'in' and can't be seen. The air is pulled in by the fuel settling back into the tank while the truck sits. Most likely the leak is before the lift pump but could also be after the lift pump. Try pumping the fuel primer and watch for any moisture on fuel filter seals or bleeders. The original copper seals on the bleeders can get work hardened and leak even if tight. Replace them or heat with torch to anneal and soften them. You can't build much pressure this way because of the return circuit to the tank.

You can slightly pressurize the fuel tank by blowing air into the vent tube. Might get a leak to show up that way.

As you said, these engines will start on the first bump even after months of sitting, if everything is right.

Don't own one, but my dad drove them for BLM in the high desert of California, said those things could climb a light-pole if gravity allowed.

He also remembers hitting a jack rabbit with the plow on the front, said the thing went up and over the truck in mid-stride.

BnaditCorps said:

Don't own one, but my dad drove them for BLM in the high desert of California, said those things could climb a light-pole if gravity allowed.

He also remembers hitting a jack rabbit with the plow on the front, said the thing went up and over the truck in mid-stride.

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How big was the plow on that thing? Are you sure you saw what you think you saw!??

It just might be a cousin to those jackalopes they got out in Wyoming.

Another Ahab said:

How big was the plow on that thing? Are you sure you saw what you think you saw!??

It just might be a cousin to those jackalopes they got out in Wyoming.


View attachment 583747

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It was a little brush plow.

who knows it may have been a coyote

I just went through fuel starvation issues on my SEE. I found a lot of odd issues like the tank vent inlet tube painted over and a possibly bad gasket on the fuel strainer but I didn't cure it until I replaced all the plastic fuel hoses with "rubber" (some sort of synthetic rated for diesel) . When searching through the history of Mercedes diesels of that era, this tubing was flagged as one of Mercedes less than great ideas. There is also a return fuel hose coming off the back of the engine located under the engine cover that is not obvious due to its routing. Its teed into the return line and looked like that might have been a leak point but that shouldn't have impacted the engine from running. The plastic fuel hose was a shrink to fit over hose barbs similar to modern heating systems. I noticed after I cut the lines off that I could spin the hose on the hose barb easily. I pulled my tank and checked the tubing for leaks or a plugged strainer and didn't find anything except for a broken wire on the sending unit (which I fixed and got my fuel gage working). There were a couple of short rubber hoses with hose clamps at the tank connections, I don't know is they were OEM but getting at them was a PITA. until I loosened up the tank straps and slid it forward so I could get at them. The various unimog pros suggested a leak under vacuum and I think that what it was. The other possible leak point they mentioned was the fuel primer pump. My unit has the newer bosch style which is the recommended fix if you have the older screw in style that has to be unscrewed to use. (I don't know if SEEs actually used the old style).

The annoying part is when I hooked up a temporary tank and slightly pressurized the system the tubing didn't leak but expect when there is a vacuum it leaked just enough. I got real good at purging the air from the filters with the hand fuel pump. My guess is replace the hoses on the tank if they exist and hose between the fuel strainer and the pump. YOu can probably skip the return line. For the short piece between the fuel shut off and the strainer inlet I would suggest a fix that came from the old Mercedes research I did which is cut a short piece of fuel hose the length of the hose barb, slit it down lenghtwise, slide it over the plastic fuel line and then put a clamp over it. Ideally I would replace this piece but didn't want to go a search for the right hose fitting to the shut off.

I also hand cut a new gasket for my fuel strainer out of sheet of Viton. I can now leave it for two weeks and it starts immediately.

flu419 said:

So a quick update & question - I drive the 'Mog on the highway at a wide open 46mph with no problems.
I did notice after a drive through the country, that after sitting for a day or two the engine acts like it is not getting fuel. Before it would start after tapping the starter, now it will spin and spin without starting. A shot of ether gets it to start up running slow then straightens out and runs regular. It will start right up after this for hours after starting. Seems like fuel starvation.

Any thoughts on this one?

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I'm going hard after one of these in the near future. Travel distance, after purchase, will be about 350 miles. Would it be better to drop the front end loader onto a trailer for that trip or more hassle than it's worth? How is the handling without the front end loader but with the back hoe at 45mph? If I do get it I'll want to try and find someone relatively local that might give me some quick pointers on working the equipment. Unfortunately the 1 local SEE that I knew of is now gone. I'm sure I can get Mog lessons from M813rc but his isn't a SEE.

And I can't find the TMs in the TM section. I was able to get the -10 of the net but would like the complete set.

mkcoen said:

I'm going hard after one of these in the near future. Travel distance, after purchase, will be about 350 miles. Would it be better to drop the front end loader onto a trailer for that trip or more hassle than it's worth? How is the handling without the front end loader but with the back hoe at 45mph? If I do get it I'll want to try and find someone relatively local that might give me some quick pointers on working the equipment. Unfortunately the 1 local SEE that I knew of is now gone. I'm sure I can get Mog lessons from M813rc but his isn't a SEE.

And I can't find the TMs in the TM section. I was able to get the -10 of the net but would like the complete set.

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In my humble opinion I would not try to drive down the road without the bucket but with the back hoe. Very unbalanced. The best configuration is with both removed. But how would you trailer the back hoe assembly? If it topples over when removed you are in deep poo-poo.

Hey all!
Retired 12B from Oskaloosa, Iowa here. I recently acquired a SEE from GSAXcess. I was astonished when I opened the cabinets and found all the tools there with about two dozen rock bits!! Only issue I could see was leaky hydraulic cylinders on the backhoe from sitting so long, and the rear remotes for the aux tools and throttle control aren't working. It ran great for a couple months, but just the other day I was driving it home and it started acting like the fuel was cutting out. I changed the fuel filters, made sure the lines and tank were clear and now it won't start. I've reprimed the filters, and cranked the engine with an injector line open and cant get any fuel. Is my injector pump toast? Thanks for any info. I'll get some pics up later.

I went through fuel issue with my rig and had some of the same concerns on my injector pump. I had a small outboard engine fuel tank with a squeeze bulb sitting around so I disconnected the short fuel line between the fuel shut off valve and the fuel strainer and hooked the temp tank up so it gravity fed so that I cut out the fuel tank and its connections as a source of problems. I then used to squeeze bulb to pump up the system. My truck would run and then lose prime. With the squeeze bulb and temporary tank it would run fine for awhile and then lose prime until I squeezed it again. I ended up replacing all the hoses and cut a new strainer gasket, including the hoses hidden on top of the tank. I was warned elsewhere that running the injector pump dry was a very bad thing as it gets its lube from the fuel. In my research Mercedes diesel car owners of that era had similar issue with the plastic fuel lines.

I also just went through a lot of electrical issues (critter ate the electrical harness behind the dash) and the final glitch after repair was that the remote throttle and the hand tool switches didn't work. There is one common 16 amp fuse (one of the few red ones) that supplies the remote throttle, the hand tools and the electric hydraulic cooling fans (and possibly the remote bucket lift?) . It is the first fuse on the left side of the #2 fuse box that is the box on the right if you are looking at it from the front of the truck. I kept loosing the fuse and finally traced it to one of the electric cooling fans which was rusted solid inside from water getting inside the motor. The fans are controlled by a thermal switch so the dead motor wouldn't cook the fuse until I started to run the backhoe for long enough to heat up the oil to the point where the thermal switch snapped. I couldn't locate a spare fan and didn't want to buy the entire cooler that EI has listed (I created a ticket with them regarding just the fan or the motor but they never replied) so I picked up some new 24 V radiator fans on Ebay and built an adaptor plate. I just installed them Saturday and ran the backhoe for three hours with no fuse issues. Not OEM but figure I would rather have new fans than 25 year old fans with a potential design defect. I tried the hand hydraulic pump system previously with no success but expect that fuse issue was making it not work. I pulled the switch Saturday and the pump obviously started and ran and the throttle sped up automatically so it may be worth tracing the fuse back to the switch panel on the back. A "dooh" moment on my part is realizing that its heck of lot easier to work on the fans and wiring with the backhoe raised to the up position.

Good luck, it will be interesting to see if the same issues are popping up with these SEEs

Cool on the rock bits, mine came with all the ones listed on the BOL but no more. I found a cross reference somewhere to the bits, they aren't standard but there are some firms that make bits that match up. I didn't get the chainsaw which is good thing as it doesn't have chainbrake and Kevlar chaps may not stop the blade as it has a lot more torque than a two stroke.