Heavy Duty Off-Roaders

Preventative Maintenance is Vital

Unidan Engineering, a Gold Coast–based niche business specialising in the restoration and modification of heavy-duty off-roaders, specifically the mighty Mercedes-Benz Unimog. After operating for the first five-or-so years at an industrial complex in Burleigh Heads, Unidan recently relocated to larger premises at Molendinar near Southport.

Heavy Duty Off-Roaders

When Diesel News arrives there’s a throng of Unimogs parked out the front, three or four undergoing spanner work in one side of the workshop, and body fabrication going on in the other. I shudder to think how cramped the previous facility must have been.

The fair dinkum family business currently employs around 10 people. Unidan founder, Daniel Mavin, works with his wife Rosina and eldest daughter Tiarni, who take care of administration and online marketing duties, respectively, while draftsman/engineer Marc Taylor is kept busy at the computer making sure every component produced by Unidan will far exceed the minimum requirement for long-term durability in arduous off-road conditions.

“Everything from our tiniest piece through to a full-blown truck is drawn in CAD (computer aided design),” Daniel explains, proudly. Referring to the CAD picture of the truck on the screen, he continues: “We’ve done the bull bar, long-range fuel tanks, front and rear winch bars, scrub bars that go over the top, custom tray and slide-on camper. We also build our own tray subframes so we order new vehicles without the Mercedes subframe.”

Interestingly, some of the standard Mercedes components, like the battery box and fuel tanks, are removed and replaced with Unidan’s custom units which are more space efficient and therefore allow better use of the available frame real estate, while substantially increasing fuel range.

Heavy Duty Off-Roaders

While each body or pod unit mounted on the back of the trucks is bespoke, in other words fitted out to individual customer requirements, Daniel points out that the same basic pod unit can be had in a variety of combinations from a camper to a full on mobile workshop.

“We just finished a new U5023 Unimog for a customer with a workshop body on the back which is essentially the same pod as the RV (recreational vehicle) but with side-opening pallet doors and storage cabinets and workbenches inside.”

The list of goods and services provided by Unidan for the Unimog vehicles is extensive and includes every conceivable option you could wish for. The company’s custom fabrication includes scrub bars, roof racks, bull bars, roll bars, winch bars, DOKA (the German acronym for double cab) conversions, extra cabs, consoles and storage, fuel and water tanks and exhaust systems.

Expedition bodies and campers can be had as built-in or slide on/off varieties and the company also builds Unimog compatible caravans and camper trailers.

Mechanical work includes restorations, rebuilds and servicing as well as the installation of rapid tyre-inflation systems, air conditioning, intercoolers and overdrive gearing.

Also on offer is a paint-and-panel shop, custom upholstery, general engineering, parts and accessories and low-voltage electrical work.

Heavy Duty Off-Roaders

In short, if it’s anything Unimog, Unidan has it covered. Nevertheless, while conceding his primary passion is Unimogs, Daniel points out that the company is willing and able to accommodate other brands of heavy-duty off-roaders, of which Iveco is the predominant contender.

In fact, Daniel tells me they recently built a support vehicle body on a Eurocargo ML150 4×4 owned by none other than intrepid Aussie outback adventurer Daryl Beattie. Beattie uses the Eurocargo as the support vehicle for his world famous off-road motorcycle adventure tours. Enough said!

Walking out to the workshop reveals a hive of activity with a line-up of ‘mogs in various states of completion. For example, at one side sit two ex-army units undergoing a full service and general going over to ready them for a second life in the civilian realm. Then there’s a tired old 1984 model camper body receiving a full makeover along with a white 1984 ex-army cab/chassis unit with restoration recently completed. Beside this is what looks like a Unimog on steroids and Daniel explains it’s the new ‘big brother’, Zetros, of which there are currently only a handful in the country.

One of the key goals of Unidan is to improve the performance, comfort and drivability of the vehicles so as to ensure maximum customer satisfaction. To this end there are a number of mechanical modifications that make a huge difference.

“We have our own intercoolers and exhaust systems which safely boost power from the standard 168hp to between 220 and 250hp,” Daniel continues. “Similarly, the standard truck will do 86km/h flat out or 90km/h with the bigger tyres. When we install a Claas overdrive and a few other bits and bobs they will comfortably cruise at 100km/h.”

Moving on, Daniel shows me a unit fitted with a 20-seat ‘mine bus’ body that’s destined for Papua New Guinea.

Heavy Duty Off-Roaders

“So far we’ve exported two units to Dubai and one to America, but if our plans come to fruition we could be exporting a lot more to America in the future.”

Next stop is the fabrication section where three more 20-person bodies are under construction. This lot have been ordered by a mango and avocado producer with three large farms in North Queensland. The bodies will be fully enclosed and air conditioned, and will be used to transport the workers from their accommodation to the farm.

It’s certainly exciting times for Unidan, with the company getting ready to launch an affordable Unimog camper in collaboration with Ballina-based Kimberly Kampers, known as the Unimog Kruiser Combo.

Other plans for the future include a Unimog repower option using a 400hp V8 diesel engine that will provide a massive boost compared to the standard engine.


All up, the future looks bright for Unidan, with all indicators pointing to exponential growth in the business. Perhaps it won’t be too many years before another move to larger premises will be required.