Zen and the Art of Unimog Maintenance

Observations from 15 Years of Mog Ownership
All photos, Copyright (C) Bill Caid, 2013. All rights reserved.

Back to Bill Caid's Home Page

Quick Links:

The links below take you to information on each of the specific subsystems of the unimog.

Zen and Art Home  Disclaimer  Errata  Parts and Parts Vendors  Truck Sales  Service and Repairs 

Engine  Fuel  Hydraulics  Radiator and Cooling   Air System  Brakes  Wheels  Tires  Electrical and Batteries 

Transmission  Clutch  Axles  Hubs  Body  Air Conditioning Tools  Safety


I have spent a lot of time taking notes and photos, keeping lists and the like, but never found the motivation to actually aggregate this information into a central location.  From time to time I get emails and phone calls about Unimogs, mostly due to my web page.  For the most part, these questions are repetitive and while I am willing and happy to answer these questions, it occurred to me that there is probably a better way.  Thus this set of pages.

The objective here is not so much to unburden myself from responding to emails but rather to attempt to codify my experiences that came with 15 years of Unimog ownership.  We had fun, no doubt, and have no regrets about either purchasing the truck or the things that happened during its ownership.  To be truthful, purchasing that truck was one of the best decisions I ever made.  We have made a set of life-long friendships that would not have been possible without that truck.  And, it allowed us to go places and have adventures that simply would not have been possible without the vehicle.

These things said, the mog is a tweaky beast.  With the correct care and feeding, you too will have fun.  Without the necessary attention, the truck WILL fail and very well may strand you in an uncomfortable or dangerous place (like Compton, CA or a foreign country but these two are really the same thing).  The key part of maintenance is being able to head off those trip-spoiling failures and to be able to minimize the impact and cost of things when they do fail.

This missive is not intended as a repair manual but rather a set of guidelines on truck ownership.  And, if you are considering purchasing a Unimog, you might find some of this information useful in determining whether the truck is right for YOU.  Mogs are cool; they get attention everywhere they go whether you want it or not.  If you have a truck, you already know what I am saying.  If you are thinking about purchasing a truck, then be prepared for the onslaught of questions and comments that you will get.  In fact, Kathleen and I developed our own "top ten" list and jokingly would say "that guy is a #4" referring to his lead question when he approaches us at a fuel stop.  One Unimog owner I know, who shall remain nameless, solved the question problem by doing a FAQ document that he put in is windshield every time he was away from his truck.  At first I thought it was arrogant and rude, but now I understand the wisdom of that approach.

Where appropriate, I have included links to photos that show the issue described.  Since the link points to a full page, you may have to scroll down to find the appropriate photos of the issue.  In other cases, I have included the photos directly as part of the description of the issue.


This is my own personal work, not endorsed, sanctioned or commissioned by anyone else.  I am solely responsible for its contents.  Any opinions expressed in this set are mine and mine alone.  The listing of a vendor or an aftermarket part does not constitute an endorsement of that vendor or part.  Nor does it imply that changes or enhancements that we made on our rig are appropriate or useful for your application.  Our rig was used for pleasure, not commercial work and therefore our criteria for choosing parts, modifications, enhancements were based on our desires and needs, not necessarily a "good, cost effective business decision".  So much for the lawyer-eese.


There are/will be mistakes in this document.  If you see something that is substantially in error or something particularly offensive, feel free to contact me a bcaid "at" yahoo "dot" com.  Assuming I don't see your comments as substantially in error or particularly offensive I will make reasonable attempts to correct the error.


The observations in this document are primarily focused on our rig - the U1300L.  The 1300, one of the "SBU" cab style trucks, is one of the more common mogs in that the European military purchased a bunch of them and they are now available as surplus.  The 1300 is a diesel and therefore comments in this document are focused primarily on diesel trucks.  Some of the information here MAY also apply to the U900 (AKA 406 or 416 models).  This document is not intended as a substitute for the shop manual or instructions on how to repair your truck.  It is, however, intended to highlight issues that may require your attention before the situation gets critical.

Each model of the Unimog product line is a bit different.  They likely share major characteristics in common, but may not.  If your model is not a 1300, then take these comments with a grain of salt until you can verify that your configuration is similar or not.

Parts and Parts Vendors

In North America, there are a limited number of competent sources for parts.  Parts can be new or used, and each kind has its own strength and weaknesses.  The list below is dynamic and there will be additions and changes in the future.  Inclusion in this list does not constitute endorsement of the vendors as to competence, reliability or delivery times.  That said, I have done business with most of these fellows over the years and have no complaints.

As a vehicle owner or prospective owner, I would caution you on the issue of lead times.  Some parts can take weeks or months to obtain, so be sure to ask about the delivery date before you place your order.  Every part in the Mercedes Electronic Parts Catalog (EPC) can be obtained, it just may take awhile.  And, there is the issue of cost.  These trucks are industrial in size, weight and design.  Heavy generally equates to expensive (you buy stuff by the pound of material, plus shipping).  Be sure you understand the cost of your items before you place your order.  The list below is in no particular order.

Eurotruck Importers (US)
Sean Philyaw
Euro-Tech Services (US)
Jim Ince
Expedition Imports (US) http://www.expedition-imports.com/
Scott Ingham
Von's Mogs (US) http://vonsmog.com/
Von Kittelberger
Terry Lee Enterprises (US) unimogrob@yahoo.com
Rob Pickering
Hans Mross (CA) http://www.unimogcanada.com/
Han Mross
Couch Off Road Engineering (US
Jay Couch

+32 56 64 43 65
AC Price Engineering (UK)

+44(0) 15242 42333
Atkinson Vos, Ltd (UK)

+44(0) 15242 62922
Merex Autovertrieb, GmbH (DE)

+49 7225 9816 39-19
Westfield 4x4 (DE)

+44(0) 15247 91968
HP-Hoster (DE)

Univoit (DE)

Nufashop (DE)

Metallbau-Feulner (DE)

United Parts Service (US)
Mike Smith

Depending on what, specifically, you are attempting to get, you may find relief at Freightliner.  Freightliner was purchased by Mercedes some years back, but every one that I have visited, save Pacific Freightliner in the San Diego area, have generally been ignorant about mogs.  If you have the Mercedes part number, you stand a chance, but expect mistakes as they don't deal in mogs frequently.  If you live near the Mexican border, Freightliner Mexico may provide a better experience (assuming the parts guy speaks English or you speak reasonable Spanish).

With a couple of exceptions, I have done business with some of he folks in the table above.  Each may have access to the EPC (you should ask) which helps remove uncertainty.

When ordering parts, you will need the VIN of your truck.  The EPC has a record of every truck sold and the specific configurations of that truck.  So when the question of "what is the gear ratio in my axle hubs?" comes around, the EPC tells all.  That is, of course, unless you modify something from the stock configuration, in which case I hope you kept the part number.

As a matter of hygiene and later sanity, I STRONGLY, if not EMPHATICALLY suggest that when you take possession of your truck that you start a maintenance notebook that stays with the truck. Write the VIN in the notebook for easy access.  Record what was done, the date, the mileage and if something was swapped out, the part number of what was purchased or changed.  If you change a fluid, record the action, date and type and brand of fluid.  Ditto for belts, hoses, brakes, etc.  My book saved my bacon on several occasions, so get a book and use it  EVERY TIME.  You could do this electronically on an iPad or something similar, but the book is only useful if you have access to it when something happens.

If you plan on doing any major repairs on your rig, I STRONGLY suggest that you obtain the Unimog shop manual from one of the above vendors.  Portions of the mog are quite complex and having the manual can make a hard job easy.  The manuals are not cheap but worth their weight in gold if it comes to that.

Truck Sales

Generally speaking each of the parts vendors also sells trucks or knows of trucks for sale.  Some are on consignment, some are for normal sale.  Each as imported or re-sold many trucks and they are competent on the issues associated with the purchase.

In the US, trucks can occasionally be found on the Unimog Exchange web site, Expedition Portal or on Craig's list.  Occasionally,  the higher-end and more expensive trucks can also be found on the Robb Report.  In Europe, Unimogs are much more common and a simple web query would bring out reasonable web sites selling surplus trucks.  You will have to confront the import laws, so if you elect to go this route I strongly suggest you fully understand the dance you will have to perform to get the vehicle through customs.  Addressing these issues are the "added value" that the folks in the table above provide.

You may, from time time, find trucks available via the internet.  My suggestion is to have a set of "qualifying questions" in mind so you can vet the truck before purchase.  In my case, my 1300 was my first truck of this type and I only looked at 3 (and not of the same model) before making my decision.  I paid more than I should have and the truck had been worked much harder than advertised, so substantial repairs ended up being required within the next few years.  Knowing what to look for could have helped that situation.  Also, willingness to get dirty and look under the hood and below the truck would have been beneficial.

Service, Repairs and Enhancements

Because Unimogs are tweaky, finding somebody who understands the complexities and variations is a difficult thing.  Each of the parts vendors MAY offer service, but I can say for certain that Rob Pickering does that as a significant part of his business at Terry Lee Enterprises.  Rob was the Unimog North America representative and knows these trucks inside and out.  He does offer an out-call service where he can come to you, but the costs could be considerable under that scenario, so I would contact him directly before you put that in motion.  Of course, if you are stuck in Podunk, KY or a foreign country that approach may be the only solution.

Enhancements to a fully-developed truck is a different ball of wax and should be approached with great care.  Usually, the premise that you know more than the Mercedes engineering design is somewhat specious.  But, should you choose to got that route, I suggest that you contact one of the parts and service vendors and ask them their opinion of your proposed "enhancement" to the truck.

Things like adding turbo-chargers can be done with low risk by the right personnel.

Getting Help

There is nothing like the collective intelligence of the web to assist you in getting your problems resolved.  There are two sources for this collective knowledge.  First is the "mog list" which is a moderated email list, but you have to be an accepted member to post to it to get help.  See http://rockymountainmoggers.com/mailman/listinfo/mog_rockymountainmoggers.com for details.  

But, that will not help you when you are in a pinch and need info NOW.  In that case, use the Benzworld.org forum:  


The Benzworld group represent the finest minds in the mog world and you can get immediate help with your issues.

Quick Links:

Zen and Art Home  Disclaimer  Errata  Parts and Parts Vendors  Truck Sales  Service and Repairs 

Engine  Fuel  Hydraulics  Radiator and Cooling   Air System  Brakes  Wheels  Tires  Electrical and Batteries 

Transmission  Clutch  Axles  Hubs  Body  Air Conditioning Tools  Safety