Repair Gearbox On Scooter
Purpose and device
Scooter reducer is designed to change the speed of rotation of the shafts, while increasing traction, it consists of:
- Primary, intermediate and secondary shafts;
- Crankcase filled with gear oil;
- Gear set;
- Drain and filler holes for oil;
- Gaskets under the gearbox cover.
Gearboxes produce two types:
- Two-stage. With countershaft;
- Single stage. Do not have an intermediate shaft.
Scooters almost always use a two-stage gear cylindrical gearbox having a high gear ratio and several times reducing the speed of the variator pulley. The principle of its work is not as complicated as it might seem at first glance. The variator and clutch torque is transmitted to the input shaft, while the gear on it is engaged with one of the gears of the intermediate shaft.
Each of them has a different number of teeth, therefore, during transmission, the rotation speed decreases. Due to the impact on it, the intermediate shaft begins to rotate with the second gear located on it. This gear interacts with the gear of the secondary shaft and also has a different number of teeth with it, which is why the rotation speed is still weakening.
The rear wheel of the scooter is installed on the secondary shaft, to which the gear torque is transmitted. During the operation of the gear system, frictional force arises, so the parts of the system must be well lubricated. For plentiful and uninterrupted lubrication of these parts, the entire crankcase is filled with oil and the gear system is in a kind of oil “bath”.
Operation and problems associated with it
The main problem that arises in the operation of the gearbox during operation is oil pollution and its untimely replacement. Clogging occurs due to the penetration of small dust particles under the gear cover, as well as due to abrasion of parts of this system. At the same time, timely replacement of oil in the gearbox can extend its service life by several times.
It is also very important the quality of gear oil poured into the scooter gearbox. If you use low-quality oil, then the gears will wear out very quickly and will soon become worthless. Replacing these parts will cost the owner much more than buying high-quality gear oil.
The first time you change the oil in the gearbox after running a new scooter. After about 400. 600 km of run. All subsequent. Or once a year, or after passing 4000. 5000 km of run. In this case, it all depends on the intensity of operation of the scooter. It is also necessary to monitor the oil level in the gearbox and top up if necessary, as poor lubrication of the gear will lead to their rapid abrasion.
To replace the oil in the gearbox system, you must first warm it up. To do this, ride a scooter 15. 20 minutes, while the dirt particles settled in the crankcase will rise and mix with oil. After that, install the scooter on a support, and unscrew the filler hole bolt. Finding it is very simple. Left (if you turn your face towards the steering wheel), in the rear of the engine.
Near it is almost always present an inscription indicating the required amount of oil in the crankcase. Then you should unscrew the drain bolt (it is small in size) and drain the used oil into a suitable container. After all the oil has drained out, wipe the drain hole and the bolt with a rag and carefully tighten the bolt back. For better density, a bolt can be treated with a resistant sealant.
Next, you need to put the scooter on the right side and pour 100.110 ml of oil into the crankcase with a large syringe. When returning the scooter to its normal position, the oil level should be flush with the bottom edge of the filler hole. After that, it is necessary to tighten the screw of the filler hole, and check the tightness of the bolt.
What “gearbox howl” and what is it connected with
If at certain speeds or loads on the scooter in the area of the engine and clutch a loud and constant howl is heard, then you should pay attention to the gearbox. Partial gears and their guides emit such a characteristic sound, especially with insufficient lubrication.
In this case, there are several options: