How to take the Gearbox off a Lawnmower. Disassembly and repair of the lower gearbox of a brushcutter, grass trimmer

Repairing the gearbox of a lawn mower wheel drive

This is a topic in the Cool Room category; The mower has an unusual gearbox. The clutch is in the gearbox, carried by a cable from the lever. Speed is constant. Gearbox is fixed, belt is permanently tensioned. Not.

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The mower has an unusual gearbox. The clutch is in the gearbox and is wired to the lever. The speed is constant. Gearbox is stationary and belt is permanently tensioned. I do not understand the principle of the clutch, when you turn the wheel by hand in the drive position, the gearbox rattles. Disassembling did not help. Another possibility was worn teeth on the clutch, but with this design, they can not fail to wear off?

Here is this mower, but the device is different, the author made a mistake

I lost a stroke on my mower, the problem was the spring (broke) of the lever that moved the cable. The second end of the spring is pulling something in the clutch. Just replaced the spring. It was under a hatch on the back of the housing.

It is strange, but there are no springs on the explosion diagram and the belt has no tension, only a thrust. And here is a photo of the gearbox is a spring, but the purpose is not clear

Many have no tension adjustment. The belt is V-belt and it can turn the gearbox for quite a long time. The explosion diagram does not show the lever (whether or not the pointer leads to it). It is pulled by a cable and can be supported by a spring. The clutch resembles a ratchet. When the lever is released, the teeth of the ratchet don’t engage. By turning the lever we pull the cable and the lever turns and moves the movable part of the ratchet along the main axis inside the gear housing. It engages with another one rigidly connected to the axis and starts to rotate. The belt transmits the rotation to the main gear rigidly connected with the main part of the ratchet through the worm mechanism.

Very often the main gear is not made of metal but of hard plastic. Accordingly, sooner or later its teeth will be sagged or sheared off.

You can see how the gearbox works here. The only differences are in size and layout, but the principle is the same:

Gearbox is another kind, I wish I had taken a photo. In the network similar did not find, as if the two crowns are shifted and the teeth catch, in appearance a strange design, the teeth are not spared, but if you twist the wheel when the pressed “progress” in the gearbox is heard and seen crackling from the slipping teeth, but when running all is quiet, just no progress. It is also strange that the visible part of the fork (bottom) does not cling to anything.

43 there are two of these parts, looks like screws.

A little like a tooth on our shallow on the “clutch” or if they died, or another problem, you need to try with the belt tension pulley, turning the gear around the axis of the wheels.

Last edited by Vladlen; 04.08.2020 в 20:58.

Repairing and lubricating the gearbox of your grass trimmer

With frequent, heavy use of the brushcutter, the gearbox may start to heat up or make uncharacteristic sounds, such as grinding. This is an indication that the machine needs oiling. If this is not done in time, there will be more serious problems (e.g. the gears will quickly wear out and need to be replaced), up to and including jamming. Other breakdowns also occur with the gear train. Repair and lubrication of the gearbox can be done independently. you just need to familiarize yourself with the peculiarities of these works and stock up on some available tools.

Gearbox grass trimmer is a node that transmits the rotational motion of the engine shaft to the blade or line. It is located on the lower end of the brushcutter bar. Transmission unit is also designed to reduce the engine speed of the grass trimmer.

The mechanism consists, depending on the brushcutter model, of several gears that rotate at high speed. As a result, they get hot because of the strong friction. If there is not enough or no lubrication, the process leads to severe overheating and failure of parts, and, accordingly, the need for complex repairs. To avoid this, it is important to lubricate the transmission unit on time. The disassembled gearbox is shown in the photo below.

Gearboxes of modern trimmer models from different manufacturers differ from each other by design and the size of the seating. It can be:

The most common diameters are 24, 25,5 and 26mm.

The brushcutters are fitted with different types of gears:

• conical;
• worm;
• spiroids;
• spur gears;
• planetary;
• wave gears;
• combined.

Drive shaft and gearbox. these are heavily loaded nodes of the grass trimmer, which are highly susceptible to wear and tear. The motion is transmitted between them because of the clutch of the gear teeth, which are placed at different angles to one another. Gears work efficiently only if there is no mechanical damage. The mechanism must not overheat, otherwise it can seize.

Damage prevention

To avoid breakdowns and subsequent costly repairs, it is recommended to follow a number of simple rules for grass trimmer operation and gearbox maintenance.

• Lubricate this gardening tool immediately after purchase. before use. Usually or Huter) applies only a small amount of lubricant, which is only enough for running-in.
• At the end of the season or before long-term storage of the trimmer for grass should disassemble the gearbox, check the condition of the bearings and gears, lubricate the unit.
• You need to add oil after the tool has been in operation for about twenty to forty hours. For heavy loads this time is reduced to twenty hours.
• Change the grease with a new one when repairing the construction or before the beginning of the season.
• When the gearbox overheats or makes a loud noise, you need to check the lubrication. If it is present in sufficient quantity, it is recommended to replace it completely with another.

So you can repair and lubricate the gearbox of a brushcutter yourself at home. Adding lubricant is not difficult, a detailed description of this process and recommendations on the selection of a suitable substance can be found in the instruction manual of the tool or on videos, of which there are many on the Internet. Most gearbox failures are typical for trimmers of different brands, they are fairly easy to eliminate if you know the correct procedure. And to avoid their appearance, it is sufficient to follow the simple rules of operation and conduct timely maintenance of the grass trimmer gearbox.

How to replace the grass trimmer gearbox: the algorithm of actions

To replace the gearbox with a similar part from the same manufacturer, it must first be disassembled and removed from the boom. Act in this case according to the following algorithm:

• loosen the tightening bolts located under the transmission mechanism;
• using round pliers, remove two corkscrew rings;
• using a puller, pull the bearings off the driven and driven shafts;
• then assemble the mechanism, in reverse order installing all parts.

Disassembled gear mechanism is shown in the photo below.

If you do not have a puller handy, you can try gently knocking the bearings down. When they are stuck and will not budge at all, you can heat them with an industrial hair dryer (at 600°C) and remove them.

It is easier to assemble the gearing assembly than to disassemble it. You may only need to tap them gently with a hammer to get them in place. After assembly, it is imperative to check that the drive shaft is rotated by hand.

When it is necessary to replace the transmission unit with a non-original part, then their interchangeability must be taken into account. At the same time, you should take into account:

• the diameter of the rod (this parameter is often 25.4 or 26 mm);
• the parameters of the drive shaft. the shape of the coupling place and its diameter (the common value is 8 mm)
• version to mount the guard.

If the considered parameters coincide, it is possible to install the part from other models.

Timely lubrication ensures long service life and no need for repairs. In addition, modern materials well protect the metal from corrosion and increase its wear resistance. Prefer the lubricant recommended by the manufacturer of the grass trimmer in use. If such compounds are not available, you should use the reviewed or other suitable properties of analogues. When it is necessary to disassemble the mechanism when making repairs, do so carefully so as not to damage individual parts.

Disassembling the grass trimmer transmission.

Related messages

• First we put the pedestrian tractor on a flat surface and find a rod with a length of about 70 centimeters.
• Bend the rod in an arc and push it into the fill hole in the gearbox until it stops all the way through the gear housing and glue the rod.
• Next, look at the oil level in the transmission. Ideally, the oil should be at least 25 cm full. Then either add oil (1.5 liters) or drain it dry (2 liters). It is necessary to fill the oil stipulated by GOST, in addition, it is allowed to mix different types of oils in any proportions.

When the mower does not start

Depending on the area of the lawn and the growth of the grass on it, the owners choose the optimal technique in terms of characteristics. It comes in several types:

An average-priced mower lasts about four seasons in the climatic conditions of St. Petersburg, Moscow or similar regions. expensive or less exploited garden helpers are able to endure in the field for 5-6 seasons.

Also the restoration of lawn mowers with their own hands will be needed in the event that the conditions of winter storage were inappropriate. For example, after use the working surfaces were not cleaned or there was no off-season preventive maintenance. As a result, a variety of problems appear:

• frequent sharpening of lawn mower blades is required;
• simply does not start the lawnmower;
• the motor starts, but after a short period of time the lawnmower stops;
• malfunctions appear at the carburetor, which requires not only disassembly, but also cleaning with repair;
• lawnmower repair with their own hands is required when there is a significant decrease in power during operation.

You don’t need to go to an expensive service center. Many problems can be solved cost-effectively and repaired on your own.

After each use of the tool it is necessary to clean the cutting elements. Change oil and service regularly to keep the risk of breakdowns to a minimum.

Grass Trimmer Top Gear Disassembly and Repair

If there are questions about the repair of the upper gearbox of a brushcutter. ask, I will give you an answer.

there is a “Tatra” lawnmower, it does not have a retaining ring through the holes in the clutch cup. Only on the bearing on the shaft side. How to remove the cup (slits on it)

at idle rpm spins the coil does not stop. Answer what can be Satol.tol@rambler.ru

Thanks for the video, I am going to rebuild my STIHL 400 this winter, so that is very helpful. informative. IMHO: the bearing is probably better to settle on the inner ring.

Hello! Problem upper gearbox scrolls along the boom with the engine. what to do? I have a petrol PIT grass trimmer. Thank you

Thank you for the informative video. Very helpful when replacing the platter.

Good day. Faced with this problem: I have a lawn mower Sterwins PBC43R 42.7 CC. Diameter of the boom is 28mm. Burned only 5 liters of gasoline (2 months of use on weekends). Damage appeared, there are traces of oil on the rubber damper clutch art. 202362 and noticeable backlash in this assembly: vertical and around the axis of rotation(rod relative to engine). Please advise: what is the approximate life of these rubbers? Is there a rubber-shock absorber under D = 28 mm and how to buy it (nowhere to be found) or it is universal with 26 mm? How much more practical and reliable is the top gearbox with damper art. 202088? Are there any advantages to the 28 mm diameter, other than strength, as I understand parts are much harder to find, I am thinking of switching to 26 mm? Thank you so much in advance!

Good afternoon I have a question for you can replace the upper gear square on the gearbox at 7 spline.

It is barbaric to press the bearing by hitting the outer ring and killing the bearing

You need to unscrew the shaft from the upper and lower reducer?

Take care people do not clog the bearings in any way.

By the way, all videos show that it is necessary to lubricate the lower gearbox, no one explains how and what lubricate the lower gearbox and how often it should be done?

Please advise what is the gear ratio of this reducer, I am Sasha, thank you

How do I replace the bushings on the inside of the rod? I bought a 9 shaft and it is thicker than a 7 shaft

Don’t ever knock the bell down like that, folks! you’ll bend it, you have to put it on the stop on the inside.

Hello, could you tell me if the bearing you replaced is lubricated??Thanks.

You should mount it on the inner rim.

Hello. Any tips on what to do with a torn thread on the binzo grasshopper, on the cylinder where the carburetor is mounted.

The bearing (ANY) on the shaft is seated only on the inner ring

Good evening, the bar is wobbling from side to side in the top gearbox what do I have to do??thank you

the dude’s been hammering the bearing at the outer rim so he can get the brushcutter back in time.

Good day. advise trimmer for grass the throttle lever in the “throttle” position is started, and then when I put the “start” the engine stalls.

after five minutes of trimmer operation, the upper gearbox is overheated, what’s the reason?

Tell me why I get too hot on the top gearbox ?

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Can you tell me if the damper has a top gear clamp (rod) inside how to get that clamp and rubber band out? Hands useless, in a vise will break, I had this clamp in the form of a tube burst today when I twisted the clamp rod, now I’m scratching my head how to disassemble and make a new one from a tube, and the second time a complete reducer to buy the expensive.

Mower is new but the upper gear does not clamp on the shaft, I’ve already tightened the screw all the way but it is only held on the fixing (anti-twist) screw.What can be the way out of this situation?

tell me, the upper gearbox is heating and the boom is wobbling what could be the reason?Mower is 1 year old, never been disassembled. thanks in advance.

Lawn mower design and common problems

It is easiest to give the lawnmower for repair, allocating a certain amount of money from the family budget, prompt and high-quality repair with their own hands is no less simple and convenient if you want to understand the design of the lawnmower and fix all the problems.

Mass and piece production of trimmers is based on the use of common technology, a typical design scheme consists of certain elements and parts, it is important to know them when carrying out independent repair work:

• upper part. The base of the entire design, where all the important elements are assembled, such as the starter, carburetor and lawnmower engine;
• middle part. Hollow rod, inside it there is a rope that connects the motor and the gearbox, which drives the cutting line for the trimmer. In this part there are mounts to distribute the weight of the entire structure and a belt to fix the grass trimmer on the belt of the person using the grass trimmer for its intended purpose;
• bottom part. It contains the gearbox and the cutting elements, which are hidden under a practical cover that protects the user. The cover provides an increased level of safety by preventing large debris, pebbles, and glass from getting into a person while operating the chain saw.

Lubricants reviews by users

Experts advise using only original materials, the characteristics of which meet the requirements of the manufacturer. If these are absent, you should clarify what to lubricate the trimmer gearbox for grass. Experienced users do not advise to use solidol, as this material is not suitable for the temperature and speed characteristics of the node, as well as the consistency. Also the given material does not have antiwear properties.

The working temperature range of solidol. from minus 40 to 65 degrees, but even with such parameters in the process of heating, the density of the material increases, and the grease itself becomes coarse. In the case of an emergency, “Lithol-24” can be used on the tool.