From the factory, a Unimog 404 uses a set of rods to activate the diff locks in both axles at the same time. These rods can be bent and the arm for the front locker is also prone to being bent or broken off. An alternative are positive locking control cables. Another benefit I gained with this conversion is the ability to lock/unlock the front and rear independently. Unlocking the front allows a much better turning radius (although these 404 diff locks are slow to engage/disengage).

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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.

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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?

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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".

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