What grease to use for grass trimmer gears

Removing and lubricating the lower shaft of the lawnmower

To remove the shaft from the lower part of the rod, first remove the reducer of the coil.

Grass trimmer lower gearbox PRORAB-8406

  • Unscrew the central fixing screw completely. On the back side of the lower clamping screw unscrew the nut and unscrew the screw completely in order to disconnect the reducer of the coil from the protective cover.
  • we loose the upper clamping screw and take out the lower part of the rod from the reducer body of the coil. Pull out the lower shaft from the gearbox side of the boom.
  • Clean shaft from dirt and smear it with grease or Lithol-24, not forgetting to clean and lubricate the socket (bushing) with splines in the gearbox.
  • Put the shaft in the shaft and the shaft in the lower gearbox of the lawnmower and line up the hole on the shaft with the hole for the central screw. Screw in the central screw. Then screw in the lower screw, clamp the lower part of the rod in the gear housing with the upper and lower screws and tighten the nut on the reverse side of the lower screw.
  • Add 20-30 ml of grease to the reel gearbox through the hole covered by the screw in the picture on the right.

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In the operation manual for gasoline grass trimmer PRORAB 8405M, 8406M it is recommended to lubricate gearbox with solidol or its analogues, as a last resort to fill liquid engine oil. Excess oil will leak out as the gearbox has no oil seal.

According to the PRORAB 8402P, 8403P, 8405P, 8406P Gasoline grass trimmer user manual, it is allowed to use two-stroke engine oil as a gear lubricant. There is no mention of solidol or its analogues.

To save yourself the trouble, lubricate the lower gearbox of your lawnmower with the same lubricant as the shaft of the boom, or pour in motor oil.

Sometimes the grass trimmer begins to rattle and make unpleasant noises during heavy mowing, indicating that the gearbox is not lubricated. This unit is considered the most loaded, so it wears out faster. If it is not lubricated in time, the drive may soon jam!

What lubricant should be used for the grass trimmer gearbox?

During operation, the mechanical part of the trimmer for grass is loaded with contact forces on teeth, reactions of resistance from grass clings (sometimes. with dirt), dynamic, impact loads due to constantly changing torque. Grass trimmer gear lubricant must fully take into account these features, so the selection of the brand must be strictly individual.

The following factors are taken into account:

  • Manufacturer’s brand. Each brand is not unreasonably focused on lubricants of its own making (you can talk about cheap Chinese products later). This applies to such manufacturers as Husqvarna, STIHL, Huter, Makita, etc. The exception is the trimmers for grass of domestic production: for example, Kalibr in the user manual does not indicate the brand of lubricant at all.
  • Viscosity of lubricant. It is known that all lubricating compositions are divided into three groups. high-viscosity (colloidal systems containing various additives), plastic compounds of universal use and solid lubricants that soften during operation.
  • Good adhesion to gearbox component surfaces, which prevents grease from squeezing out into gaps or out of the assembly.
  • Degree of gearbox grease consumption. Here you have to rely on your own experience and recommendations of specialists, since some trimmer manufacturers, trusting in their own service centers, do not give any clear recommendations concerning the period of operation between two lubrication intervals.

Lubricant consumption also depends on the temperature at which it retains its lubricating power. When the gearbox is heated up to 40°C, the operating conditions are considered satisfactory and lubrication is sufficient.

It is believed that there is no universal lubricant for the trimmer gearbox for grass, but this is not entirely true. In fact, a suitable lubricant would be one that has the following components:

  • Antiwear additives that do not contain toxic lead;
  • Solid lubricants with the presence of graphite or molybdenum disulfide (the latter is preferable, because in this case the lubricating power is fully preserved for a wide range of shaft speeds);
  • Only mineral (inorganic!Only mineral (inorganic) oils with high purity.

Lithium-based Gear Grease OREGON or Champion EP-0, domestic compositions Oleo-Mas, Lithol.24, or Azmol 158, as well as those recommended by the manufacturer of a particular model of grass trimmer.

Breakdown 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.

grease, grass, trimmer, gears
  • Lubricate this gardening tool immediately after purchase. before using. Generally or Huter) applies only a small amount of grease, just enough for the running-in period.
  • At the end of the season or before long-term storage of the grass trimmer, you should disassemble the gearbox, check the condition of the bearings and gears, and lubricate the assembly.
  • Grease should be added after the tool has been in operation for twenty to forty hours. For heavy loads this time is reduced to twenty hours.
  • It is essential to change the lubricant when repairing a machine or before the start of the season.
  • When a gearbox gets too hot or noisy, check for grease. If it is present in sufficient quantity, it is recommended that it be completely replaced with another.

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

Grass trimmer gearbox design

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

The mechanism consists, depending on the brushcutter model, of several gears rotating at high speed. As a result, they heat up due to the strong friction. If there is not enough lubricant, or no lubricant at all, the process leads to severe overheating and failure of parts, and, accordingly, the need for complex repairs. To prevent this from happening, it is necessary to lubricate the transmission unit in time. The disassembled gearbox is shown in the picture below.

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

The most common diameters for round seats are 24, 25.5 and 26 mm.

Mowers are equipped with different types of gears:

  • tapered;
  • worm;
  • spiroids;
  • cylindrical;
  • planetary;
  • wave;
  • combined.

The drive shaft and gearbox are heavily stressed parts of the grass trimmer that are highly susceptible to wear and tear. The motion between them is transmitted because of the interlocking of the gear teeth, which are placed at different angles to each other. Gearing can only work effectively if there is no mechanical damage. The mechanism must not overheat, otherwise it could seize.

Servicing your petrol grass trimmer

Most brushcutters and trimmers have a flexible shaft in their design. Its condition should be checked at least once every 50 working hours. To perform this operation, you need to remove the boom tip, pull out the shaft and inspect it, then lubricate.

To care for the shaft will be suitable for inexpensive materials, it is more difficult to find them for the gearbox trimmer for grass. What to lubricate this mechanism with. depends on the tool manufacturer. It is best to use materials that contain molybdenum disulfide. The latter ensures smoothing and filling of cracks in the working surface, so it is especially valued by users.

Important: Using a lot of grease with high density leads to overheating of the mechanism, increased friction of the working pairs and fuel consumption. The selection of materials and preventive maintenance should therefore be handled responsibly.

Gearboxes: types and features, choice of lubricant

Gearboxes are used to drive the rotating mechanism and “make” it work. Its design can be different, depending on the purpose of the tool.

They are also used to drive the brushcutter mechanism. Reducers for grass trimmers of various designs are available on the market.

Popular are two- and three-stage models of twin or unfolded circuits, which are resistant to stress and have a high level of efficiency.

  • Worm. The compact tool is the most common type. It features increased torque, simple design. The worm model doesn’t make any noise, but gives high performance. Self-locking function is a feature of the tool.
  • Globoid worm. It has a slightly convex shape, high drive power and increased torque.
  • Cylindrical. Cylindrical gears, variable design, high power. Uses a service life of 25,000 or more. hours.
  • Conical. Circular, straight toothed wheels are used in the design. It is distinguished by its sturdy operation and simple design.
  • Conical-cylindrical. Designed for large equipment only. Has a low load capacity.
  • On-tool. It is mounted on the output shaft, without additional gears, connections. The model is compact and lightweight.
  • Planetary. One of the most powerful tools, which has a complicated design. Mainly used in mechanical engineering.

The gearbox of your brushcutter is basically of the helical-worm type. It provides high quality work of trimmers.

Extraction and lubrication of lower mower shaft

To remove the shaft from the lower part of the boom, first remove the spool gearbox.

  • Unscrew completely the central fixing screw. On the reverse side of the bottom clamping screw unscrew the nut and unscrew the screw completely to disconnect the reel gearbox from the protective cover.
  • Loosen the upper clamping screw and remove the lower part of the rod from the reel gear housing. Remove the lower shaft from the reducer side of the rod.
  • Clean shaft from dirt and grease it with oil “Shruz-4” or “Lithol-24”, not forgetting to clean and grease coupling (bushing) with splines in reducer.
  • Install the shaft in the rod, and the rod in the lower gearbox of lawnmower and align the hole on the rod with a hole for the central screw. Screw in the center screw. Next, tighten the lower screw, clamp the lower part of the rod in the reducer housing with the upper and lower screws and tighten the nut on the back side of the lower screw.
  • Add 20-30 ml of grease to the reel gearbox through the hole closed by the screw on the right side of the photo.

How to choose the right grease

During operation, the nodes of the mechanism are loaded with contact forces on the teeth, resistance reactions when debris enters, as well as dynamic and shock loads. Depending on the characteristics of the load, you should choose what to lubricate the trimmer gear for grass.

The following factors must be taken into account when selecting a trimmer

GREASE THE GRASS CUTTER GEAR BOX/ HEAD GEAR/ GREASE INNER SHAFT/GREASE SHAFT ROD OF BRUSH CUTTER,

  • manufacturer’s brand;
  • Viscosity of the lubricant (this parameter is selected according to shaft torque)
  • adhesion to the surface of the parts of the assembly;
  • intensity of grease consumption (ambient temperature, type and volume of works to be taken into account).
grease, grass, trimmer, gears

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If the required lubricant is not available, a general-purpose. The latter must contain some components:

  • anti-wear additives (no toxic lead);
  • highly refined mineral oils (inorganic)
  • solid lubricants with graphite or molybdenum disulfide.

How to lubricate the gearbox of a grass trimmer?

Lubrication of the gearbox is done by putting grease into a special technological hole without dismantling the unit.So, in order to lubricate the grass trimmer, it is necessary to perform a number of simple actions:

  • Disconnect the power tool from the mains before starting work. In gasoline units, to avoid leaks, it is desirable to drain the gasoline (or during the work, make sure that the device does not turn over)
  • Use the tool supplied with the grass trimmer to unscrew the plug in the gear housing
  • If we change the grease completely, then wash the gearbox. For that we pour some kind of cleaner (white spirit, gasoline, etc) into the body of the trailer.), rinse the reducer and pour off. This procedure is repeated several times until the machine is completely clean
  • Put new grease in the gearbox. For this purpose we put a tube or syringe spout into the hole and squeeze 2 5 ml of grease there
  • Screw the plug in
  • Turn the shaft a few times by hand, then run the brushcutter for a short time at a low load so that the grease spreads evenly over the friction surfaces