Tamiya King Hauler Tractor Truck





Whether you like cars, airplanes, helicopters or boats, I’m betting heavily on the fact that you would delight in building the King Hauler, one of the finest radio control scale trucks on the planet. I have been building models of all types for more than 35 years and I can say unequivocally that the King Hauler was the most satisfying modeling experience I have ever had. I was thrilled with the detail and design of the King Hauler (and tanker trailer). Every bolt, gear, clip, metal part and plastic part fit exactly as it was intended and, believe me, there were plenty of parts! I also took great satisfaction in constructing things like a gear differential, a 3-speed gear box, leaf springs, and other elements of this scale behemoth. I can best describe my experience building the King Hauler as a cross between building a static car model and a radio control helicopter. Painting the King Hauler requires some familiarity with spray paint or air brushing and the rest is essentially a mosaic of mechanical parts, the assembly of which I found extremely enjoyable. Before you conclude that I’m one of those sit-in-the-shop-for-a-month-building type guys, let me tell you that my normal mode is to get through the building process as soon as I can in order to operate whatever I am building. This was different. The King Hauler (and I suspect other models in this line) coaxes you into enjoying each step of the process and rewards you at the end with an awesome working model. In my opinion,

Tamiya has succeeded in its goal to be “first in quality around the world” with the King Hauler.

To successfully build the King Hauler, I recommend only moderate hobby skills. What is more important than previous experience is patience and a willingness to carefully read instructions. On an initial review of the parts in the kit, the King Hauler kit can, no doubt, send waves of panic into the hearts of a complete novice. But that is what separates this kit from lesser competitors. The extraordinary level of detail in the model demands a considerable stock of screws, gears, pinions, bolts, nuts, washers, metal parts and plastic parts. However, with basic tools, the moderately skilled modeler can tackle this project with relative ease.

We built the King Hauler and tank trailer stock and added the motorized legs, trailer light kit and multi-function unit, which breathes sound and light into the beast. Our overall cost was just shy of $1,100, not including finishing supplies such as spray paint, polishing compound, Bare Metal Foil trim and glue. The entire project can take from 25-40 hours, depending on your pace.





Scale: 1/14
Length: 23.62 inches (600mm)
Width: 7.20 inches (183mm)
Wheelbase: 17.60 inches (447mm)
Front Tread: 6.14 inches (156mm)
Rear Tread: 5.43 inches (138mm)
Weight: 6.17 lbs. (2800g)
Chassis: Aluminum ladder
Suspension: Solid Axle
Damper Type: Metal friction
Drive Train: Gearbox (3-speed)
Gear Ratio: 10.6:1 – With the 3-speed gearbox, 10.6:1, 17.7:1 and 32.4:1 are possible
Differential Type: Bevel Gear
Engine: Electric 540 type motor
Wheels & Tires: Chrome/Radial Body Type: Styrene(plastic)
Radio Control Unit: (not included) Can be operated with a 2-channel radio but a 4-channel system is recommended for potential future options. Battery: Requires a 7.2V battery and charger


Scale: 1/14
Length: 32.05 inches (814mm)
Width: 7.32 inches (186mm)
Rear Tread: 5.43 inches (138mm)
Weight: 9.70 lbs. (4400g)
Chassis: Aluminum ladder
Suspension: Solid Axle
Damper Type: Metal friction
Wheels & Tires: Chrome/Radial


56501 – Tractor truck electrical unit set
56503 – Tractor truck oil shocks
56504 – Roof spoiler
56506 – Animal guard
56507 – Telescopic antenna
56508 – Truck aluminum front wheels (1 pair)
56509 – Truck aluminum rear wheels (1 pair)
56510 – Tractor truck sound effects set
56502 – Semi-trailer light set
56503 – Tractor truck oil shock set
56505 – Motorized support legs
56509 – Truck aluminum rear wheels (1 pair)





  • Awesome scale appearance
  • Excellent detail
  • Minimal glue
  • Incredible functionality
  • Modular build for later add-ons




  • MFU instructions vague in areas










The instruction manual is complete. Written in English, French, German and Japanese, the 31-page manual packs everything you need to know about building the King Hauler into descrete steps. There are several features of the manual worth noting:

  • Every item shown has a corresponding bag, blister pack or plastic tree code so you can easily locate the item.
  • The smaller parts are illustrated in actual size on the left margin of each page so there can be no confusion about which part to use on a particular step.
  • Where necessary, the instructions supplement the illustration with a description of the steps to be completed.
  • The kit includes thread lock and grease. The instructions clearly indicate where to use them on the model.

Do not be intimidated by the “jam packed” appearance of each page in the manual. If you take things one step at a time, nothing in the manual is truly daunting or confusing.







If you simply intend to operate the King Hauler with a 2-channel radio, everything you need is included in the kit except the radio equipment, 7.2V battery pack (and charger) and an electronic speed control (ESC), which can be purchased for less than $40.00 from most any retailer that carries Tamiya products. If you want to “kick it up a notch” like we did, you’ll need the following:

  • Tamiya trailer unit (we picked the tanker)
  • A 4-channel radio system with 3 servos (we used a Futaba Attack 4VWD)
  • Multi-Function Unit (which contains an ESC, so no need to buy one)
  • Motorized Legs Kit (to automatically couple and uncouple the trailer)
  • Trailer Light Kit (plugs into the Multi-Function Unit (MFU)
  • Spray Paint (or airbrush paint). We used Tamiya’s Spray Lacquer
  • Clear Coat – We used Tamiya’s Clear Spray
  • Standard plastic model cement (we used Testors)
  • Standard modeling tools
  • 7.2V 3300 NiMH battery pack for peak performance






There are so many parts in this kit that I thought it was worth noting that an organized setup from the beginning will make this project a whole bunch easier and more fun. Everybody knows that projects tend to grow like moss after a few days, so I took a moment to organize myself:

  • I took old servo boxes and emptied the contents of the screw bags into them, keeping the labels for size and shape reference. This helped immeasurably.
  • Keep each blister pack part in the blister pack until you use it
  • Keep the box bottom as a place to house the truck body and other partially completed parts.









I chose Tamiya’s TS-18 Metallic Red for the body. Painting is not difficult, but it does benefit from patience and a bit of painting knowledge. Only after I painted my rig did the guys at the local hobby center advise me that metallic paint is one of the most difficult types of paint to apply with a can. Oh well.

For the uninitiated, let it be known that I have spray painted a grand total of 5 models in my 35 years of modeling. You can do a good job by following a few simple guidelines.


First, build, fashion or buy a paint booth. They really help. My 12-year old son helped me build the booth pictured above using pre-fabricated 2ft x 2ft sheets of coated masonite from Home Depot and 1” x 1” strips of wood for support. I added an exhaust fan at the back. I have since learned that bathroom fans work the best because they move more air than the computer fan I used and because they don’t throw sparks! (Just imagine what a sparking fan would ignite in your bathroom!) We also built hooks into the top of the box and tossed in a lazy Susan to make quick work of rotating the parts during painting.

I began by applying three light coats of red over the entire body. These are called “tack coats” because they provide a sticky surface for subsequent coats to adhere. The Tamiya lacquer dries very quickly in low humidity so you can get your tack coats on in a short time span. For most paints, the tack coats are followed by “wet coats” that go on with a smooth appearance. Metallic paints are a bit different and applying wet coats often makes them run. For this truck, I simply increased the amount of paint in each coat until I achieved the desired depth of color. When I was satisfied with the overall color, I applied Tamiya’s clear coat lacquer. Two coats and I had a nice shiny finish which I buffed (7 days later after the paint had sealed) using Tamiya’s special buffing compound (get that where you buy your paint). I finished the cab by waxing it with car wax! That’s right, it works! The result is a shiny, lifelike finish. I am certain that folks who are either experienced with an airbrush or who have good spray can technique can produce far better results than what I got.





Rather than rehash the instruction manual, my aim is to provide highlights from the construction process with photos that capture the detail and excitement of the build.

Servos lead off the build process. Once you get the custom horns attached to your servos (we are using standard Futaba S3003’s here) it’s on to the fun stuff. I was delighted by the aluminum ladder frame structure.of the model. Similar to a real rig, everything begins with two long braces that form the undercarriage of the truck. Once you construct the leaf springs (boy are these cool) it’s on to the rear wheel differentials. This is where Tamiya shines.


One of the details I really liked was the spring leaf shock system. Using real metal spring leaf assemblies for each wheel set and combining it with aluminum, spring loaded shock absorbers, Tamiya gave the King Hauler a realistic and “truck-like” suspension system.


The gears that make up the differential assemblies fit nicely into their housings and mesh especially well once you apply dabs of grease (which is supplied with the kit). Be sure to use the included grease because it is friendly to plastic! These differential assemblies give the opposing rear wheel sets the ability to rotate at different rates as the rig rounds a corner. That is serious attention to scale!


The King Hauler sports a 3-speed transmission!! With the multi-function unit (MFU), you can bring the transmission to life with actual truck shifting and authentic gear sounds. Even without the MFU, the ability to realistically bring your rig up to speed is an engineering joy in a model.



Realism rules with the King Hauler, from tires to taillights. If you have the MFU, you can integrate the lights during assembly of the kit. In fact, we recommend building the kit with the MFU if you can afford to buy everything at once.



There are a number of things you can do to make your King Hauler turn out perfectly:

  • Make sure you check the part number for each item you use during any given step. Some screws look similar but are not. Tamiya has intelligently packaged the screw bags to avoid confusion among parts in a given bag, but if you do not read the instructions carefully, you may dip into the incorrect bag, leaving you short on another step.
  • Trim parts carefully. Tamiya designed each plastic part such that plastic tabs used to attach the part to the tree are on the least visible side of the part when assembled. Regardless, you should use a sharp #11 type blade to remove every tab. To clip parts from the tree, I recommend a clipping tool with extremely sharp blades to ensure clean cuts.
  • Always apply thread lock and grease where indicated. When constructing the gear box with shifter, be sure to amply lubricate the slide bar which moves the active gear among the different speed gears. This will relieve the shifting servo of unnecessary strain when shifting gears.
  • Be extremely careful when using CA glue on the underside of painted parts. I had some CA seep through a glue joint and completely ruin a painted piece with a white fingerprint. When working with ordinary plastic cement, apply it with a toothpick instead of the tube itself. This eliminates seepage and helps keep your hands free of cement residue, which can ruin other parts of the model you touch.
  • Use “Bare Metal Foil” to chrome parts of the truck that do not come pre-chromed. This foil has been around for years and it works great to add detail to the truck. I used some on the center line ridge of the truck’s hood.
  • Slice a square of 800 grit sandpaper and slide it behind the grill. This will give a solid black look to the grill rather than allowing wires to show through!




Take great care when applying the decals included with the King Hauler. Unlike similar “peel-n-stick” decals, I don’t recommend using window cleaner or any other substance to help slide the decals into position. The adhesive may weaken if you do this. Besides, careful technique will result in a successful application. Your best bet is to peel away about a half inch of backing from the edge of the piece you are applying. Using a scissors, cut the backing flap, leaving the adhesive portion open to application. You can then position the decal, adhere the unbacked portion and then slowly peel away the remaining adhesive while pressing out the air bubbles along the way.

I have included a number of photos that illustrate the decal application process. In some places, I trimmed away decal material even though not required by the instructions. It’s all a matter of personal preference.







The tanker goes together fairly quickly. After having built the cab, you should be completely familiar with the instruction routines, parts and overall process. There is little to paint on the tanker (and what you can paint you don’t have to) so building the tanker should take no more than 5-7 hours. However, if you choose to add the motorized legs and light kit, expect to spend an extra few hours. When we ordered the components for our King Hauler, the motorized legs unit arrived after we had constructed the cab’s coupler unit, giving us some modification work to get the entire assembly to work properly. Getting the automatic coupling to work is not difficult, it just requires your full attention.

Rather than track the entire build process with the tanker, I have included highlights of the process. By far, the most painstaking process is adding the decals. Using the process I described above, I was able to get the Shell decorations on without a hitch!

The tanker is beautiful. When you attach it to the rig, the detail and impact will blow you away!





The tanker goes together fairly quickly. After having built the cab, you should be completely familiar with the instruction routines, parts and overall process. There is little to paint on the tanker (and what you can paint you don’t have to) so building the tanker should take no more than 5-7 hours. However, if you choose to add the motorized legs and light kit, expect to spend an extra few hours. When we ordered the components for our King Hauler, the motorized legs unit arrived after we had constructed the cab’s coupler unit, giving us some modification work to get the entire assembly to work properly. Getting the automatic coupling to work is not difficult, it just requires your full attention.

Rather than track the entire build process with the tanker, I have included highlights of the process. By far, the most painstaking process is adding the decals. Using the process I described above, I was able to get the Shell decorations on without a hitch!

The tanker is beautiful. When you attach it to the rig, the detail and impact will blow you away!





Most of the tanker is metal. The frame, tank and front fender are covered in a blue protective plastic, which you should peel away, but only when you are ready to work on the covered part.
The motorized leg kit (Item 56505) requires you to create a completely new set of legs from the stock tanker kit. In addition, you need to mount the leg motor, battery holder and trigger switches. The process is not difficult, but does require care. The only area I ran into difficult with was the mounting of the leg servo tray on the King Hauler. The metal tray is supposed to slide beneath the battery platform, but the platform has a ridge that prevented the metal tray from sliding in fully. I used a Dremel tool to trim away the battery mount ridge and the tray fit perfectly. This was the ONLY modification I had to make on the entire project.



The semi-trailer light set (item56502) is easily installed during construction. The lights to the semi-trailer are bundled into a single plug that attaches to the MFU by way of a port installed on the back of the cab.



There are no differential gears in the trailer so assembly of the rear axels is straightforward. Suspension is similar to the King Hauler, with leaf springs and spring shocks.



Mounting the main tank is fun and easy. It only takes 4 bolts! Once mounted, you adorn it with a nice milled aluminum upper deck and other structures (pipes, ladder, tank ports, handholds, etc.) that give the tanker its detailed appearance.


Remember, avoid using window cleaner or other substances to slide your decals in place. The illustrations below show that decals can be applied straight simply by attaching one end carefully and then peeling the backing as you press the decal in place. To ensure a good look, trim as closely as possible to the artwork on the decal sheet. Once the decal is down, use the polishing cloth (included with the tanker) to rub out the air bubbles trapped beneath the decal.










I can’t say enough about the multi-function unit (item 56511). This is what separates the King Hauler (and other Tamiya tractors) from the pack. Don’t be intimidated by the tangle of wires and plugs. Take one step at a time, beginning with the most important one: labeling each wire with the included color-coded stickers. This simplifies everything and makes connecting each light quite simple.

Monster Sounds

When I unpacked the speaker included with the MFU, I was tempted to use it for my home audio system! It’s huge! Seriously, this puppy can put out sound. It turns out that you can use that output when running the King Hauler outside. I was testing the truck in my driveway and my wife walked out and said she thought the FedEx truck was parked at the front door. That’s what I’m talkin’ about!

The sounds are incredible. Digitally recorded from a real truck, the sound effects are integrated with the controls so every function is accompanied by the appropriate sound:

  • Engine starter
  • Engine idle
  • Air dryer
  • Revving
  • Running sounds (differs depending on whether a trailer is connected)
  • Shifting (up and down shifting)
  • Air release (two types: driver initiated and after stopping)
  • Exhaust brake
  • Brake
  • Short and long horn sounds
  • Turn signals (two sounds: one standard and one for left turns)
  • Hazard signals
  • Backing alarm
  • Parking brake
  • Engine stop
  • Alarms (when pressure in air tank is low and when engine stop w/lights on)
  • Coupler sounds (if you have the motorized leg unit, coupling will be audible)

The full range of sounds can be controlled with a 4-channel transmitter. The volume is controlled by adjusting the knob on the truck-mounted control panel.




Lights and Vibrations

The MFU comes with a “vibration unit” that literally vibrates the truck at idle to give the visual effect of a large diesel engine at work. You can adjust the degree of vibration by rotating one of the pots on the ain unit.

The lights are just awesome. Tamiya has taken extra steps to ensure realism by supplying special metal backing plates for the head lamps. These give the lamps a halogen appearance when switched on. The running lights, fog lamps, turn signals, speed lights and brake lights all work precisely. At night, the red brake lights get brighter when you apply the brakes. Tamiya has not missed a thing!

Driving the King Hauler

We built and tested the King Hauler on a 4-channel Futaba radio. If you plan to install the MFU, you must have a 4-channel radio to take advantage of all functions. Driving the King Hauler does require you to study the MFU instruction guide pages 8-10 (keep them nearby until you remember the commands). Unlike typical transmitter controls, the trim tabs on your radio are used to set the function you wish to control. With the trims in proper location, you can operate the function by toggling the gimbals as desired. I will not rehash the entire compliment of controls here but I will note a couple of interesting ones:

  • Steering & Shifting Templates: The MFU (and motorized leg kit) come with a plastic steering template to stick over the left stick on your transmitter. This limits stick movement to 90 degree increments and makes controlling the semi easier. You can obtain an optional left-stick shift gate (template that keeps your left stick in one of three vertical columns), although we were able to drive successfully without it by mimicking the stick postions illustrated in the manual.
  • Trims: Make sure you return all trims to neutral position after you execute any of the commands that require a change of trim. Nasty things can happen, especially if the left stick, left-right trim is off center (this messes up your gear shifting).
  • Braking and Backing Up: To apply brakes, simply move the stick backward. If you are using a shift gate, pull back in whatever column you are in. If you have the time and distance, try to downshift to first gear before applying brakes. This appears more realistic. Don’t worry, sliding the stick back will not jam the truck into reverse. To access reverse, nudge the stick back to neutral and then pull back again for reverse. The reverse “beeping” will sound.
  • Motorized Legs: The motorized legs are controlled by the right stick. To activate the control, you slide the left trim over to the left and toggle the left stick to the left. You will know that you are in leg mode if the leg servo moves when you move the right stick fore and aft. If the horn activates, you are still in horn mode! The instructions on leg operation are included in the leg kit, not the MFU book. Before you couple and uncouple, be sure the trailer’s light cord is unplugged from the cab! The motorized legs are powered by 4 AA-cell batteries and a separate motor tucked beneath the trailer frame.
  • Other Commands: The lighting commands are fairly simple and are explained in the MFU manual. You will have loads of fun testing and enjoying the different functions.

Click to view video of the King Hauler! For lower speed connections, scroll to almost the top of the page and look for the video icon on the left.We tested the King Hauler on standard asphault roads and indoors on low carpet. Both surfaces work fine. I would not drive the truck on anything higher than commercial height carpet. Doing so will not only cause your truck to accumulate fibers, but also risks tipping the rig on turns. The King Hauler can work up a head of steam on asphault. To get our video shots, we pulled a dolly along side the truck as it paced through its 3 gears. It easily hit 20 miles per hours (from our best guess). Any more speed is really unnecessary with this model. We had the most fun at lower speeds when turning and backing. The acceleration curve is fantastic. If you nudge the stick slowly, you can achieve a scale start and smooth climb to full speed. Using a 6-cell 3300 mAh NiMH battery pack, we got run times of 8-10 minutes at full throttle (with sounds at full volume and vibration unit at 75%). Just driving around in the cul-de-sac yielded 15-20 minutes of horn-honking, light-blinking fun.


Conclusion & Follow Up

After running the King Hauler and tanker through the paces, we did notice some areas of the model that may vibrate loose during normal operation:

  • On step 11 of the cab assembly, I highly recommend using thread lock on the 3 x 20mm bolts that secure the leaf spring assemblies to the rear wheel axels. During the final video sequences, several of these bolts vibrated loose and completely dropped out the assembly. Fortunately, we noticed immediately and made repairs before any damage was done.
  • On the 20th run, we noticed that the brass fitting came loose from the leg activator retention piece on the coupler device (cab). We noticed this because the transmitter no longer activated the motorized legs. We reassembled the fitting with thread lock to prevent future mishaps.

Other than those minor items, the King Hauler performed flawlessly. Right now, this is the most fun radio controlled model I have!


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