Introduction: The Gotruck: a Practical, Efficient Work Vehicle for Third World Countries
In this instructable, I'll be covering the steps I took to build an efficient, reliable, cheap work truck that you too can build, and use as a tractor to move loads, plough fields, and can greatly one's improve quality of life. The trucks are called different things in different countries: "Girico" in Brazil, "Ledok" in India, "Gotruck" in the United States, and many other names. In this tutorial I'll be referring to this any many other like projects as a Gotruck, due to its mechanical similarities drawn between a go-kart and a truck.
The breakdown of how these work is that you will take a small engine, normally under 20HP and put it into a truck or car with a manual transmission, made possible by a very simple gearing reduction. Because the engine is usually air cooled and has 1 or 2 cylinders, it is incredibly easy to work on and maintain. The ignition systems are easy to work on, the fuel consumption is minimal, and it is very cheap to run. Depending on your circumstances, you may choose to use a gasoline or a diesel engine. In either case, the installation is pretty much the same. Depending on where you are reading this, a price range you can expect to pay is between $500 - $1000 US dollars, if you have to buy all of the parts. Depending on how you set the engine up, it can later be used to generate 120v of usable electricity for tools or lights, etc. making for a great offgrid all purpose utility truck. Keep in mind that, depending on where you live, it may not be legal to operate such machines on the road, so be aware of any local impositions that you will have to deal with if you decide to use this to move goods to the market.
This project isn't for the faint of heart. That being said, I learned more about machines and engines from this one project than any community college course ever taught me. Be prepared to learn much about engineering, mathematics, metal working in many of its forms, as well as gaining new skills that will give you more hands-on experience than most of the population ever dreamed of.
You really can't lose!
**Authors Comment** While I may not be a master of the 3D printer like many of the other people on here, (I love your guys work by the way!) I do love mechanical engineering, in many of its forms, primarily in large scale machines that have real world applications and practicality, and I work with what I've got. If you want to have a discussion related to full scale engineering projects with regards to motorized vehicles and machines, let me know! I would love to share my ideas and hear yours!
With that being said, let's begin.
-A truck/car, MUST HAVE MANUAL TRANSMISSION! - If you can buy a used truck with a blown engine, this will be the best option. For the best results, you will need the stock flywheel and clutch that came with the vehicle.
-Next, you will need a small gasoline/diesel engine under 20 horsepower (imperial) because of the type of drive we will be using.
-Two pulleys will be required, which will be touched on in a further step.
-Access to a scrap pile, with all sorts of different cuts of metal. You will need to be able to weld or have someone else do it, but keep in mind that this will add to the total cost of the project should you decide to hire out the dirty work.
-Various nuts and bolts
A drill (power preferred, hand drill can be used as well)
A welding machine
And finally, I cannot stress this enough, a good socket set.
Old Truck/Car: $100-$500
Scrap metal for engine bracing: -$50
Tools: Can be borrowed from some auto parts stores, FREE-$400. Ask friends, rent tools, etc.
Step 1: Selecting the Vehicle
For this project you will need a body-on-frame style truck, because we will probably remove the body to save weight. You can keep the body on but this may reduce your usable power. I used a Geo Tracker and swapped an old Jeep body onto it. Look around in the junk yards and ask the neighbors if they have any old trucks with a bad engine. You can find such project vehicles on Craigslist, quite regularly for under $500. It would be in your best interest to get one with the engine still in it, even if it is blown or unfixable. We only need parts from it.
Whatever is selected, make sure that it has a standard transmission and working clutch.
SIZE AND WEIGHT: You should consider how large the vehicle needs to be. It may seem silly, but wheelbase is a very important factor to think about if you even consider going into the offroad scene. Have you ever noticed how short and stubby Jeep wranglers used to look? (1980's-2000's) A shorter wheelbase crawls over rocks easier, and is less likely to hit the undercarriage when navigating over bumps. A vehicle that is too wide and bloated or HEAVY is more likely to get stuck... (Looking at you, 2020 Wrangler) so it's best to not use a truck that weighs 5000 lbs. Also, it can really tear up your grass. Go for something lighter, more like in the 2000-3000 lbs range. SUVs in this class are the most maneuverable, and and since most of them that weighed that little were made over 10 years ago, it'll be easier on your wallet if you have to buy a base to start from. If you're looking for something in this class, some SUVs I would recommend that are affordable are the Geo Tracker, Suzuki Sidekick, Suzuki Samurai, Toyota Rav4 (2 or 4 door version) or a rusty Jeep Cherokee or Wrangler. Go for a BODY ON FRAME design! It'll be so much easier to fix or modify if need be. Remember, if you are only planning on using it offroad at low speeds, rust holes really aren't that big of a deal. Watch out for frame rust though, the kind that is deep and pitted or that has cut the frame in half entirely. Those are nothing but headaches.
Now if you plan on just cruising over a grassy plain or mostly flat
ground, a long wheelbase 2 wheel drive might be in your best interest. If you foresee ever having to drive through mud though, get a 4x4 model. 2 wheel drive vehicles are great for moving tools, small loads or people on grass. A long wheelbase is good in case you have to tow a trailer. It is good in case you need a long flat bed to haul hay, stray, logs, dirt, or anything else really. Some vehicles I recommend for a starting base are any Ford, GM or Toyota pickup trucks.
You're mainly looking to get a frame that isn't eaten in half by rust. Look for one that's strong, and preferably still has the paint on it. Beggars can't be choosers, though. There are ways to stop rust by using different methods of painting old transmission fluid on the part, mixing candle wax with grease and spreading it over the affected area, and many others. Surface rust isn't a big deal. I happened to get lucky and find a SUV that has almost no rust, and another one of the same model that was destroyed by rust. The guy sold them to me for $300 and that was the best purchase I've made in years. I have a whole extra set of drive-train components to work with, and a good frame. SUSPENSION: Suspension is what softens the bumps between your wheels and the vehicle's frame/body. If you're going slow (under 15 mph) and the suspension is a little saggy, it ain't much to worry about. If you're going to be hauling heavy logs, you might want to consider going for a truck that has good springs and shock absorbers. You can always use some redneck ingenuity to figure something out, though.
COST/PURCHASE: Depending on your negotiating tactics, you may opt to either just buy an old truck or car out of a junkyard, or you could buy one from a neighbor. A good frame and transmission from the yard may run you from $300 to well over $1,000, depending on the make of the vehicle or how rare it is. Remember: The people that run the junkyard make these kinds of purchases and sales each and every day. They are trained to sap your pockets as much as possible, to squeeze out the very last penny in order to line their own pockets. They're trained negotiators, so be mentally prepared before dealing with them.
Usually you'll have to buy one part of the car at a time, since some
states/governments don't allow the sale of an entire car from the junkyard. Remember, you are searching for a utility vehicle to do work with. Not your next ride to work or wherever. Surface rust is not a huge issue, those cigarette burns in the seats aren't gonna lower your social status. The cracked fender isn't going to be seen by everyone you drive past. You wouldn't believe how many good cars are scrapped because they are considered "too ugly" to be driven. Need I remind you of the Cash4Clunkers program?
What about neighbors or people in your area? If you live in the more rural parts of the world, there may well be a broken down junked car or truck with a blown motor, perfect for what you need! In many cases, these piles have sat on the lawns of their owners for many years, and now they may well be ready to get rid of the wreck. Talk to a wife if you can. Generally they can talk some sense into their husbands if he is being particularly stubborn about a sale. Don't pay more than $400 for something, especially if it has a blown engine. If the engine runs, great! You can sell it and maybe get your money back.
Remember: Pay as little as possible.
Step 2: Getting the Engine
Here's the fun part: finding an engine to put in the truck. I recommend that you get a gas/diesel engine over 9HP but not over 25HP. The larger then engine, generally, the more the fuel consumption. You need to do the calculations and figure out how much power you will need depending on what you will be hauling.
You can either use a gasoline or diesel engine. Diesel engines are generally longer lasting due to the fact that they are built of stronger metals and run at lower RPMs, but they can be hard to work on should they break. Gasoline engines are simple in comparison, but they don't produce the kind of low end torque that diesels do. Most gas engines today are made from aluminum, lessening the total weight of your finished vehicle.
Choose what is practical. What fuels are readily available in your province or country? Diesel? Gasoline? Or perhaps you have access to other fuels, such as kerosene, popane/LPG, crude oil, or woodgas?
Most of the fuel varieties available today can be ignited by a modified internal combustion (Gasoline) engine. Diesels and crude oils as well as waste vegetable oils are ignited by compression, therefore a diesel engine may be your best bet. Note that some of these fuels require modifying the engine into which they may be burned, for fuels may burn differently resulting in more or less power, or different mechanical operations at play within the engine they power.
What to look for: When searching out a reliable engine, there are some things to consider as far as the physical reliability goes. First off, check reviews for the model if possible. Others before you have purchased such engines and they have found many of the common flaws and failures of some models, and may steer you towards a possibly cheaper and more reliable option.
While old iron may be better, you can't always find parts for it. Yes yes, I know that 60 year old lawnmower with the 12 horsepower horizontal shaft engine may be very attractive, but always consider the possibility that the engine could have tens of thousands of hours on it, and parts for these old beasts aren't as common as they once were. Will you pay more in the long run for something that might fail sooner? Should you decide to purchase an old engine to use, may I recommend the Wisconsin engine company. They ostly stopped producing engines for the general public over 20 years ago, but their engines were made of cast iron and could last a lifetime if properly maintained. They're one of the most renowned names in American engine manufacturing, simply for their rugged reliability. However, since they are mostly not producing products anymore for people like you and me, some other well known and reliable brands are Briggs and Stratton (Aluminum blocks, but parts are everywhere) Kohler (Basically anything they made before 1990) Onan (Electrical problems were more common in these engines.) and Kubota. (Multi cylinder diesels) One engine that I am seeing more and more is the Duromax 18hp single cylinder. This isn't an ad, I'm just telling you about it because it has design features I think it has strongly in its favor. It's also cheap to buy and modify.
Features to consider:
Does the crankshaft have bearings? Yes, it may sound like a stupid questions but many lawnmower engines produced by both Briggs and Kohler don't have a bearing on the crank case cover. That means the crankshaft is riding on only a thin film of oil separating the hardened crankshaft and the soft aluminum. I've seem dozens of engines die due to this easily preventable design flaw. Look at the diagrams of your engine and look for the roller bearing that slides over the crankshaft and seats in the cover. This will be more reliable and may well save your engine should it lose oil pressure for any reason.
Cast iron or aluminum? Air cooled cast iron engines (were) generally more reliable than their aluminum counterparts, because the iron doesn't expand as much as the aluminum, and it's harder. Usually, if an engine is made of iron, it will have separate roller bearings for all of the moving parts instead of the cheap aluminum the manufacturers get away with using. Iron, however, is much heavier, so consider that too. Iron also rusts. An iron engine, however, can also be rebuilt more times and resurfaced more than aluminum because of its hardness.
Is the camshaft made of plastic? If you see an engine that has this "feature," back away slowly. Just no.
Is the carburetor made from plastic? Run away.
Is it made by Tecumseh? Get out of there like you've got a pack of wolves after you.
RESOURCES: Check your local classifieds for Go Kart engines, old tractors,gas powered golf carts, concrete saws, mowers, large power equipment etc. Check craigslist, Facebook Marketplace, and other online stores for used Briggs and Stratton engines. Their Vanguard line is readily available, and most horizontal Vanguard engines are between 16-22 horsepower. Most can be had for $100-$400 depending on condition.
Step 3: Gearing Ratio/Drive Gear
When you drop a tiny engine into a big truck, it's not going to move with the 1:1 engine to transmission ratio that all cars and trucks have. You'll need to gear it down. By having a 4:1 ratio, the flywheel of your engine will turn over 4 times to one to one of the transmission input shaft. Lower gearing ratios means higher torque, at the expense of top speed. You can gear it so low in fact, that a 6hp engine could pull a small truck up a 45 degree angle! The wheels may turn slower than the earth does each day though...
Also, will you use a #40 chain to drive two sprockets? What type of clutch setup will you use? Why not consider a belt? A belt will slip instead of break or fly off like a chain would. A belt may be cheaper in the longrun to maintain as well. What about physical cut gears? This would be the most reliable and long lasting option, but it will be very expensive to engineer and design, and finally to build.
If you want to see some ideas on how this can be done, check out the following videos. The first one is my own build:
Step 4: Weight Reduction, Bro!
First, no. Don't even think about trying to push around a 7,000 lbs truck with 9hp. It just ain't worth it. Strip that thing down to the frame, and tack up a support for the peddle assembly and the steering column. Once that is done, you can weld on a seat or a bench making it easy to carry a couple passengers, should you desire to.
The goal here is to make the most basic transportation possible at the lowest fuel cost. This means that you may be deprived of such luxuries as a floor, bumpers, or fenders. Just rip off as much junk as possible and you'll be fine. Get the chassis down to under 1,500 lbs if at all possible, and your build will be faster and able to pull more.
Step 5: Remove the Old Engine
This part is easy. Just undo all of the wires and mounting bolts, wrap a chain around the engine and use a tree branch or a lift to pull the engine out. A chain fall is easy and cheap, hydraulic lifts are easier but usually are owned by professional mechanics. A come-along is $20-30 for a cheap one and will serve you well for many years, too, so consider this option.
WARNING: Engines are heavy. Like most things that have any weight, engines like to go DOWN very fast and they make quite a dent when they land. Should your engine slip out of the lift and fall for any reason, make sure that you are far enough away that it won't cut off your foot or worse! Use secure bracing and make sure that you have properly secured the engine in the chains BEFORE you lift! This is vitally important for your health and safety.
There are a number of videos on YouTube about how to do this exact thing:
Step 6: Transmission Adapter
You'll need to figure this one out. Every situation is unique. If you need help, consult with one of your mechanic friends or a mechanical engineer, possibly a machinist. We're a proud bunch but know a thing or two about turning metal rods.n
Your adapter must be balanced, and suitable for high RPM applications. Use grade 8 or better bolts. You can't afford to cheap out here. look at the pictures to see how I did it. I used an old metal shaft, and welded a thick plate on the end which I lined up in the flywheel and marked off and then drilled out the 6 holes for the bolts that hold the two pieces together. Do you see the pulley I used? Here you can attach any sized pulley you choose, or a chain sprocket. Just make sure that it is up to the task of delivering high torque for long periods of time.
If you want to use a belt drive, I recommend the 4/3vx size. My belt is a 4/3vx280 size if you're curious. It is similar in size to many motorcycle drive belts but much thicker. It too, has four tracks so slipping off of the pulley is nearly impossible.
Step 7: Attach the Engine
Measure, measure, measure. Measure twice, count once. Shall I stress it more?
You MUST make good measurements and line up the pulley/sprocket of your engine with the adapter to your transmission. This is vitally important, because if not done right, your belt or chain will wear prematurely and your engine may shake itself loose if not attached properly. Use the original engine mount if possible, or weld in the base to the truck frame. The most simple way to do this is welding a flat piece of 1/2" thick steel plate just in front of the transmission, and then lining up the engine afterwards. Look up YouTube videos on how to do this. Check out the videos in a previous step.
The rest is just welding or bolting everything in place, and attaching your belt/tensioner or chain drive. Once this final step is done, you should be ready to drive it!
Step 8: Enjoy Your Ride!
At this point, you should have a complete rolling machine that moves under its own power. If you have had the brain power to read through this entire Instructable, then you can 100% build one of these trucks I guarantee! They're cheap, simple alternatives to most ATVs and cost not even 1/4 of the price to build, compared to buying a decent used ATV or side by side. Maybe even less! This just goes to show that when you apply your mind to something, it can be done for less than the usual cost and effort.
The total build time to get this project running can take up the space of a couple to a few weekends, depending on how complicated your build is. Just remember: Simple is better.
If you have enjoyed this Instructable, please give it a vote! It is part of the 2020 "Make It Move!" Contest. I sincerely hope that you have been able to save money and fuel costs, and that the build can improve the quality of your life and save your back too. Many places don't have all the resources that we have here in the USA, and if you are reading from one of these areas, I commend you for making the best of everything you have! Keep up the hard work!
Participated in the
Make it Move Contest 2020