How to Lubricate a Stihl gas trimmer Reducer
Sometimes, in the midst of intense mowing of grass, your trimmer begins to make unpleasant, grinding sounds. This complains about the lack of lubrication of the gearbox. The most intensively loaded unit of the device. And soon, these “warnings” may be followed by jamming of the drive.
What grease should be used for the trimmer gearbox?
In the process, the mechanical part of the trimmer is loaded with contact forces on the teeth, resistance reactions from adhering grass (sometimes with dirt), dynamic, impact loads due to constantly changing torque. The grease for the trimmer gear must fully take into account these features, so the selection of the brand must be strictly individual.
The following factors are taken into account:
- Brand of the manufacturer. Each brand is not unreasonably oriented on lubricants of its own manufacture (you can talk about cheap Chinese products later). This applies to manufacturers such as Husqvarna, Stihl, Huter, Makita, etc. The exception is domestic trimmers: for example, Caliber in the user manual does not indicate the brand of lubricant at all.
- The viscosity of the lubricant. As you know, all lubricant compositions are divided into three groups. Highly viscous (colloidal systems containing various additives), plastic compounds of universal use and solid lubricants that soften during operation.
- Good adhesion to the surface of the gearbox parts, as a result of which the lubricant is not squeezed out into the gaps or out of the assembly.
- Gearbox lubricant consumption rate. Here you have to rely on your own experience and the recommendations of specialists, since some trimmer manufacturers, relying on the availability of their own service centers, generally do not give clear recommendations regarding the period of operation of the gearbox between the two lubricants.
The lubricant consumption also depends on the temperature at which it retains its lubricity. When the gearbox is heated to 40 ° C, it is considered that its operating conditions are satisfactory, and there is enough lubrication.
It is believed that there is no universal lubricant for the trimmer gear, but this is not entirely true. In fact, a suitable lubricant will be one in which the following components are present:
- Anti-wear additives containing no toxic lead;
- Solid lubricants with the presence of graphite or molybdenum disulfide (the latter is preferable, since the lubricity is fully preserved for a wide range of shaft revolutions);
- Only mineral (inorganic!) Oils, with a high degree of purification.
The lithium greases Gear Grease OREGON or Champion EP-0, domestic compositions Oleo-Mas, Litol.24, or Azmol 158, as well as those recommended by the manufacturer of a particular trimmer model, fully meet the mentioned requirements.
How to lubricate the trimmer gearbox?
In the upper part of the housing, where the gear block is installed, there is a technological hole, which, when the trimmer is operated, is plugged with a screw. This screw is unscrewed, and 1.5. 2 ml of grease is introduced into the hole using the nozzle on the tube. If the lubricant was purchased in a different packaging, then for this operation a regular disposable medical syringe is also suitable.
After that, the screw is installed in its original place. This procedure, regardless of the user’s recommendations, should be performed every 10. 15 hours of operation of the trimmer in operating mode. Other reasons for updating or replacing the gearbox lubricant are independent minor maintenance work (for example, cleaning and washing the gearbox gear before the summer season), repair of the unit, preserving the trimmer for the winter period, etc.
If the gear unit is disassembled, it is recommended to completely remove the remains of the previous grease from the surface of the parts, even if it does not have any signs of oxidation and contamination. And only then apply new grease. After applying the lubricant, it is recommended to turn the shaft manually several times, and make sure that the lubricant is evenly distributed over all parts of the gearbox.
When lubricating, special attention is paid to the following elements:
- Flywheel: on its surface, as a rule, the remnants of grass adhere intensively, and thickened grass juice creates additional resistance.
- The starter coil dog, which is constantly in contact with the grooves on the flywheel when the drive is turned on. In this case, not only mechanical wear occurs, but also mechanochemical corrosion of the flywheel-dog joint, since the materials for this pair are different (the flywheel is aluminum and the dog is steel).
- Bearings, if their seals are worn, and through them the grease is squeezed out. In this case, the unit begins to vibrate intensively when loaded. This happens with Chinese-made trimmers, so it’s worthwhile in the future to think about replacing the bearing assembly with a better one, for example, from the Swedish company SKF.