About 100 feet into a offroad trip, the generator in the mog died in a cloud of smoke. The mog was waiting patiently at the bottom of a hill when an onlooker pointed out the smoke coming from under the hood. I quickly popped the hood and saw that it was coming from the generator. While I grabbed the fire extinguisher, my friends unplugged the giant cable that runs to the voltage regulator. By the time I got back around the front of the mog, the smoke was diminishing so I decided to grab the camera and take a picture of it in it's death throes.
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Once home, I removed the generator from the mog and took it apart to try to determine the possible cause of it's demise. I say "try to determine" because even though these are simple devices, they still baffle me. To my uneducated eye, I can't find anything really suspicious except for a bare wire on the armature. Is this a cause or merely a symptom? The only thing conclusive is that most of the components have a really strong burnt electrical smell.
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Generator housing showing field coils and smoke damage. In the second image, the upper coil has the most damage but it was mounted in that same position so if it is just smoke damage then that would make sense.
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Commutator and armature. Notice the bare wire and some of the solder balls at the bottom of the commutator that have not been knocked off yet. There were a lot more before removing the generator from the mog and there were also some solder balls on the connections to the brushes.
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Brushes look to be in good shape. The brush connection that looks burnt was mounted at 12 o'clock so I think that is just smoke damage. The second image is the back of the belt pulley and some generator blood? Possibly cooked grease from the front bearing?
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A couple of pictures of the inside of the voltage regulator. It was suggested that a possible cause of the generator failure could be a stuck contact in the regulator. When I opened up the regulator, I thought the front contact looked like it was melted together but it would still separate. I don't know if that contact has always looked that way or maybe it is the culprit in bringing an early end to my day of wheeling.
A couple of years ago I picked up a set of reproductions of some MB technical drawings on German Ebay. The prints were decent quality but I scanned them in at a high resolution and cleaned them up a bit. They are suitable for printing out at up to 11" x 17".
Woohoo! I finally ran across a good deal on a two-speed crawler box for my mog. These have always been expensive when they turn up, and as of late, I have seen people selling them for crazy prices. I was driving home from a couple of side jobs and was thinking about what I could spend my extra cash on. I got home with the intent of buying a decent tripod but pulled up the Pirate 4X4 forum and saw Doug''s post advertising the crawler box. I called immediately and they were mine. Quite a bit more than a tripod, but it was one of those ''do what you got to'' deals. These crawler gears should make me the winner of any tortoise race. They take an already respectable 113:1 crawl ratio in low range first to an amazing 348:1 in crawler first. They supposedly don''t like the skinny pedal but since it just idles through pretty much anything now I don''t see that will be a problem. And since I have done the 8-speed conversion, I get 4 gears in crawler instead of two.
So, I now have: 4 gears in high range, 4 gears in low range, 4 gears in crawler range and 4 gears in reverse. Does that make it a sixteen speed?
Somehow, just like most of my projects, the winch installation mushroomed into a much bigger project. This project morphed into the frame shortening, bed chopping, bumper building, battery relocating and oh yeah, winch installation project. I wanted to mount the winch on the rear of the mog to help balance the nose heavy weight distribution of an unloaded unimog. Unimogs are designed to perform their best carrying their full load. But for serious offroad a few tweaks can help a lot. The battery relocation was done also to move more weight towards the back as well as provide more clearance under the side of the truck. With the frame and bed chops, I now have a 90 degree departure angle and a narrowed bed that won''t get hung on everything and that I don''t mind laying the mog on. My bed is like a big rock rail. The only drawback is that with a rear-facing winch, I still don''t have any way to winch myself forward. But that doesn''t mean that is hasn''t gotten some good use, pulling out other vehicles, as well as pulling me back out once. I still want to have a winch mounted towards the back but pulls to the front. You never know. . .
I think this is one of the best modifications you can do to a 404. The 404 comes stock with a six speed transmission but it is possible to convert one to eight speeds. Without adding any gears! Most of the conversion is removing stuff from your tranny - not adding to it. To explain how this works, forget everything I just told you. The 404 comes stock with an eight speed tranny (4 speeds in high range/4 speeds in low range). Apparently, Ma Benz decided we didn''t need eight stinking gears and blocked off third and fourth gears in low range. This conversion primarily consists of undoing MB''s factory hobbling of this tranny and adding an extra lever to activate high or low range. It is interesting to note that MB continued to sell six and eight speed trannys in later models using the same "modification". You don''t gain anything on the low end or on the top end (which could use another gear or two) but you pick up two intermediate gears that help fill a big gap between the old second and third gear ratios. Makes for a much more comfortable trail riding rig. No more listening to second gear screaming or third gear lugging. Another side benefit is I now have four gears in reverse. What!?! You would be surprised how convenient that is. Before the conversion I had two gears but they were both very low geared and if you had to back up for any distance, it could be quite painful. Plus, it freaks people out when you start changing gears as you drive in reverse.