Replacement of gear gear gear screwdriver: step-by-step repair

A sudden power tool failure always happens at the most inopportune moment, especially when there is a volumetric work ahead. The characteristic hum of a motor without rotating the cartridge or crackling inside the housing often indicates a failure. planetary reducerIn most cases, the problem lies in the breakdown of one or more gears made of metal or composite materials.

Replacing these items on your own not only saves you a lot of money on service centers, but also extends the life of your tool. Makita, Bosch or interscoll They have similar mechanical designs, so the algorithm will be universal for most models, but before starting work, you need to make sure that you have the right spare parts and specialized lubricant.

Ignoring the first signs of malfunction, such as periodic jerks or heating of the body, can lead to more serious damage, up to the burnout of the engine anchor. So if you notice that the tool has stopped developing its previous power or emitting unnatural sounds, it is better to start the diagnosis immediately. In this article, we will discuss in detail the process of disassembly, defective and assembly of the mechanism.

Diagnosis of gearbox malfunctions

Before disassembling the tool, you need to precisely localize the problem. Often users mistakenly sin on the battery or start button, whereas mechanical failure requires a completely different approach. Initial inspection allows you to determine whether the sheepskin is worth making, or it is easier to buy a new screwdriver. Listen to the sound carefully: a grinding noise usually indicates worn gears.

The main symptom of wear of gear is a backlash of the cartridge when rotating with the hand or a characteristic crack under load. If the engine is buzzing, the shaft is spinning, but the cartridge is standing still, then the teeth on one of the gears have been cut off or the shaft has broken. satellite, which often crumble into pieces when solid particles enter the mechanism.

⚠️ Warning: If you find melted plastic around the gears after disassembly, it may indicate overheating due to lack of lubrication or excessive load, in which case you can not do with simple replacement of parts - you will need to check the windings of the engine.

Accurate diagnosis sometimes requires partial disassembly of the body to visually assess the condition. solar-cog Metal shavings on the old lubricant are a sure sign that the mechanism is running dry or the resource of the parts is already exhausted. The presence of a large amount of abrasive dust inside the gearbox indicates a violation of the tightness of the housing.

Required tools and materials

You can't have a good job without the right equipment in the workplace, you'll need not only a set of screwdrivers, but you'll also need specific tools to work with small parts, and if you don't have the right equipment, you can damage the fasteners or the gears themselves during the dismantling process.

First, prepare the set. sledge-and-cross screwdriver There are different sizes, because screw screws can be different, some models, especially professional models, may need torxes (stars) or hexagons to disassemble, and tweezers to extract small springs and locking rings will also be useful.

• 🛠️ A set of screwdrivers (PH1, PH2, SL3, SL5) and bits.
• 🧴 Plastic lubrication (lithium or graphite) for gearboxes.
• 🧹 Scabs or paper wipes to clean the old lubricant.
• 🔨 A light hammer and a wooden expanse (for knocking out the shafts).
• 🧤 Protective gloves and glasses for eye safety.

The use of solidol or litol in modern high-speed gearboxes is not always justified, as they can thicken in the cold or leak out when heated. power-toolIt retains its properties over a wide range of temperatures.

The process of disassembling the body and removing the gearbox

Disassembly of screwdrivers is a process that requires careful and systematic approach, and the main goal at this stage is not to damage the plastic latches of the case or lose small screws. The location of the fasteners may differ from manufacturer to manufacturer, but the general principle remains the same.

First, you need to remove the battery and disconnect the cartridge. Depending on the model, the cartridge can be attached to a thread or a Morse cone. To remove the threaded cartridge, you usually need to twist the locking screw inside it (left thread!) and pinch the cartridge in the vices or through the key to twist it counterclockwise.

Then we twist all the visible screws around the perimeter of the case. Often one or two screws can hide under stickers or rubber pads, so carefully examine the tool. After removing the fixture, carefully spread the halves of the body, trying not to pull sharply so as not to damage the wires going to the start button or LED backlight.

⚠️ Warning: Before the halves of the body are completely disconnected, be sure to disconnect the wires from the start button and the engine, if they do not have quick-release contacts.

Once the engine and button are removed, attention is shifted to the mechanical part, the gearbox is usually attached to the front of the body or in a separate casing, remove the entire assembly so that you can freely access the insides, and you can now start disassembling the gearbox directly.

Defective and replacement gears

Once in your hands, the gearbox is a complex system of shafts and gears, and to figure out what to change, you have to break it down into its components. Usually, the design is a set of planetary steps, where each one increases torque, and it's best to do it in stages, by photographing or remembering the order of the parts.

First, take the top cover off the gearbox, and underneath it, you'll see the first stage. solar-glue And you can check them for chips, cracks, or slick teeth, and even a micro-crack on the gear tooth will eventually cause the knot to collapse completely, so you'd better replace the questionable parts right away.

If one gear is damaged, it is recommended to change the entire set of gears of this stage or even the entire gearbox assembly if it is sold as a spare part, this is due to the fact that worn parts could develop response parts, and pairing a new gear with the old one can cause rapid re-wear.

When you assemble, pay attention to the condition of the shafts. If they have a shaft or bully, it can cause beats and noise. In some cases, the shafts can be welded or replaced, but more often they change the entire knot. Make sure that the sliding bearings (sleeves) do not have a critical backlash.

Why do plastic gears break down?

Plastic gears (sintered metal or reinforced plastic) are often deliberately put as a "weak link"; when a drill is jammed, the gear breaks, saving the engine and gearbox from more expensive repairs, a kind of safety mechanism.

Comparison of materials gears: metal or plastic?

Modern screwdrivers use gears made of different materials, and each has its advantages and disadvantages. Understanding this difference will help you choose the right parts and mode of operation of the tool, the choice of material affects the durability, noise level and cost of repair.

Metal gears are typically made of hardened steel, are highly durable and can withstand significant overloads. However, metal requires high-quality lubrication and makes more noise when it is working, and when jammed, the metal transmission can transfer torque to the engine, which can break the anchor.

Plastic or composite gears (often sintered metal with graphite or special polymer) are quieter and cheaper to manufacture, and their main advantage is safety for the engine: at extreme loads, they simply lick, preventing the windings from burning, but the resource of such parts when intensive work is lower.

Characterization	Metal gears	Plastic/composite
Strength	High, can withstand shock loads	Medium, afraid of sharp jerks
Noise at work	High noise levels	Working quietly.
Engine protection	Low (combustion risk)	High (working as a safety lock)
Part price	More expensive.	Cheaper.

When choosing a spare part, focus on the recommendations of your manufacturer Makita or DeWaltIf you're changing gears in a professional tool for heavy work, you'd better prefer metal. For home use, where the loads are moderate, high-quality composites are also good.

Assembly of the gearbox and lubrication of the mechanism

Making a gearbox is the reverse of disassembly, but with a critical addition: applying lubrication. The amount and quality of the lubricant determines the life of the repaired unit. Don't spare the lubrication, but don't cram the gearbox to the point of failure to avoid overpressure and oil squeeze through the glands.

Put it on. plastic It's very thick on all the gear teeth, shafts and inner walls of the gearbox body, and you have to pay special attention to the friction points of the bushings and bearings, and it's got to be thick so it doesn't leak out when it's hot, but it's fluid enough to get into all the friction points when it's working.

Collect the planetary steps in sequence, checking the free passage of each shaft. The gears should rotate easily, without jamming. After installing the upper gear cap, check if it is tightly sat down and if there are gaps. If the design provides for sealing rings, make sure that they are in their places.

Place the assembled gearbox in place in the screwdriver body. Connect the engine wires and buttons while observing polarity. Before you twist the body, make a test run without the cartridge (or with a key inserted) to make sure that the mechanism rotates smoothly and without extraneous sounds.

⚠️ Warning: After assembly, let the tool work at idle speeds for 2-3 minutes, this will allow the lubricant to be evenly distributed throughout the friction nodes. If you smell burns or get a lot of heat, stop immediately and check the assembly.

Frequently Asked Questions (FAQ)

Where can I find the number of the gear to buy a spare part?

The part number is usually stamped directly on the gear itself or listed in the exploded-view diagram of your screwdriver model. You can also find the gearbox catalog number assembled on the case or in the instructions, which is often easier than looking for individual gears.

Can you lubricate the reducer with ordinary solidol?

Solidol is only a last resort for inexpensive tools, it tends to thicken in the cold and dry at high temperatures, which will lead to accelerated wear, and it is better to use specialized lithium lubricants labeled "for power tools".

Why does the screwdriver hum more after replacing the gears?

New gears, especially metal gears, take time to grind, and a humming boom in the first hours of operation is normal, but if the noise is accompanied by vibration, it may be that the gears did not fully sit on the shaft or the assembly is disturbed.

Should I change gears on a cheap Chinese screwdriver?

It depends on the cost of the parts. If a set of gears costs more than 50 percent of the price of a new tool, it's not cost effective to repair it, but if you're only changing one piece of gear, or doing it for the sake of experience, it's worth the effort.

How to prevent the failure of gears in the future?

The main cause of failure is to operate in the "shock" drill mode without switching to the appropriate mode or using blunt drills. Watch the sharpening of the tooling, do not press hard on the tool and let it rest so that the gearbox does not overheat.