I've recently joined the world of mog ownership. One week in, I have now tackled quite a few small wiring jobs, and sound deadened the entire cab. Wrapping up the last bit of work tonight, I needed to crawl under the truck (which has been stationary since my drive to LA from San Francisco last week).. and of course, I see a few oil spots on the driveway, followed by noticing fresh fluid on the front differential, the bottom of the transmission, and the center pto (hydraulic pump).
Tomorrow in the daylight I'll check all the fluid levels, but if anyone wants to hazard a guess as to what these leaks could be, or give me some idea of what to look at other than fluid levels, please do My next plan is to towel the areas dry and try to gauge the severity of the leaks over the weekend (in the light.. as it's really difficult to assess the situation in the dark and 34F weather)
Not having owned a mog (or even a truck!) before, I'm a little unfamiliar with what is typical.. on my usual vehicles, this amount of fluid leak would be very unacceptable, but I'm wondering if seeping a bit is just part of owning a Unimog.. of if I'm going to need to replace some serious seals in the near future. Thoughts appreciated.
(This is a 416.115 DoKa)
The oil leak.. (at least it appears to be oil to me)
Front differential, camera facing the back of truck
Facing driver side wheel
Looking further back, noticing a few drops on the bottom of the Center PTO
From beneath the bed, looking forward.. PTO on right, back of transmission above the pto and more to the center. Fluid on tranny is red (as I would have expected)
Transmission (center PTO to the right)
To the right of the transmission, and about 12" up.. no clue what this is
that being said.... how much was it being used before you bought it? If rarely then you got to remember that the seals swell some once they are resoaked in oil. Anotherwords.. use the mog and some of the leaks could well actually reduce over time.
Is this a torque converter truck? I don't really think that any of the fluid should be red, unless it's some strange synthetic. The trans and axles use GL4 gear oil. It's not uncommon for vehicles that have sat to leak when put back into use. The seals set to one size, and the first time it gets hot they can leak. George is right, if it is a seal, it may slow or stop if you keep using it. Just keep an eye on the levels so you dont run low.
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Seth
71 416Mog, 92 fj80 (worst fuel pig EVER), new 85 300tdt for dad, 2000 KLR650, 84 300td STOLEN!
Coach-- I think it was sitting in a barn in Belgium for a few years with a bad caliper. Scott changed all the fluids and put about 30-40 miles on it with no leaks or other unknown issues, before I came and picked it up. She made the 400mi drive from SF to LA (at 52mph ) like a champ.
Esde-- nope, standard 6spd (w/ 2 reverse) 416.
I think the red fluid is actually the center PTO? Can someone confirm for me this is the PTO dipstick? (it's directly behind the PTO lever, and offset to the side the central PTO is located on, so i think this is a logical conclusion) I'm not really familiar with hydraulic fluid enough to know if this is.. it looks like ATF to me haha.. very red and about as thick as oil. So if this is the center PTO (or even if not), what variety of fluid should I fill it with, since it's nearing the lowmark.
EDIT: The fluid on the front diff smelled pretty funky but looked like oil. Never dealt with GL4 before, but based on the funky smell, I'm guessing it's gear oil. I cleaned it off, and we'll see if any re-appears. The hubs do not have any visible leaks, so I don't think I need to check the hub levels (does anyone disagree?).
The rear leak was a little bit of what looks like ATF (that I think is hydraulic fluid-- see above about PTO), and also some "sludge". The sludge was coming from the top of the tube going to the rear differential, where there is a boot, and the boot is "loose" at the bottom (this is visible in my last photo from last night.. captioned "no clue what this is" .. guess in the dark i didn't see the boot and tube to diff). I can easily put 2-3 fingers inside the boot, and when I do so, I get the following sludge... (there's probably about 3x this much still in the boot)..sludge probably just built up from over the years? I guess it's possible this is lubricating grease too (with some dirt and randomness mixed in), and the boot is supposed to be tight and full of grease. Can anyone confirm?
The engine oil is dead center between the low and high marks. The PTO dipstick was at 25% above the low mark. I don't see any other obvious dipsticks to check.. still trying to find the tranny dipstick (under the shift boot covers?)
Last edited by atom : 12-15-2007 at 03:17 PM.
Reason: added photos
The dipstick in the photo is for the tranny. The bottom PTO runs a hydraulic pump, that might have the red fluid in it. It should have its own tank somewhere for it. Did this truck have a crane or backhoe at one time? They would have needed the extra PTO driven pump. As for the boot, it should be tight. There could be some grease in there, but it looks like your output tranny seal might be leaking. Keep an eye on the tranny level. If it were my truck I would just change every fluid in it. Then I know what I have in it, and when it was last changed!
Thanks Von. Upon further inspection, the rear torque tube boot (at the tranny ) is cracked in several spots, so this will have to be replaced.
The fluids are all fresh, Scott (at EI) changed them when the truck came off the boat, before I bought it. I wouldn't have driven a freshly purchased unimog 400mi if i wasn't 100% sure the fluids were all new and at the right levels.
No clue if it had a crane or hoe-- I don't think so (it didn't in any of the pictures of it sitting in a barn in Belgium), but then again they took a lot of stuff off it before selling it (bed, schmidt/radiatorskid plate, some of the trailerbrake lines), and whatever the hydraulics were going to.. there are 3 lines.. 2 of them (driver side and middle one) just "loop return" to each other, and pass. side one is capped. It has the Werner style cast mounts on the back of the frame, for either a winch, or i guess a 3pt ag mount, so maybe they were running something ag related off the back?
edse, you mention GL4 non-hypoid in the tranny AND axles. I have been under the impression that it is only necesary in the tranny. The axles and hubs can use your gear oil of choosing. Anyone care to confirm or deny?
you are correct about GL4 in the trans only. I prefer to keep only one on hand, so GL4 for the whole thing! Though, there is no bronze int the hub, so GL5 is fine. I've read conflicting reports that the GL4 requirement might only be for 404 mogs, but have not had the time to research it further. One is a post from Jack, the other two are translations from a german site. If I have it saved from my old ibook I'll find it and post for you all to debate.
Just reading my Case 406 manual, transmission fluid specs are "API-GL-5". Not a mechanic (but learning quickly), but do I interpret this correctly to mean GL-5 is okay?
My next plan is to towel the areas dry and try to gauge the severity of the leaks over the weekend (in the light.. as it's really difficult to assess the situation in the dark and 34F weather)
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