The gearbox after opening the housing.
The left cover after opening the housing.
On the bottom of the cover is a lot of oil mud in the area of the gearbox as well as in the crankcase .
The gear controller moves the sprockets on the shafts by using the two sliders.
The shift lever moves the gearwheel segment, which is turning the gear controller.
The gear wheels are arranged on the two shafts.
Before starting to disassemble the gearbox, it is advisable, to prepare a clean place for the parts of the gearbox.
I have used an old desk pad.
Here are all the parts of the gearbox. I placed them in the order, as they were mounted in the gearbox.
Warning!
The disassembling as well as the assembling of the gearbox has to be made without force!
All parts of the gearbox can be removed and inserted without tools easily by hand.
In the meantime i have disassembled the gearbox a few times to make the pictures.
The best way is to stard in a defined position.At first we remove the big gearwheel with 21 tooth from the auxiliary shaft.
The pictures always shows the gearbox, before the step has done.
Now we remove the main shaft.
The two gear wheels, which were on the main shaft, can be removed now.
At next we remove the shifter shaft, which holds the two shift sliders.
Now its time to remove the first slider an the gearwheel with 21 tooth.
And now the second slider and the gearwheel with 18 tooth.
Now we remove the cleared spring and springsupport disc.
At next it is possible to remove the auxiliary shaft.
The gear controller and the parted geaerwheel can be removed together now.
The latch and the sping for the latch will be removed.
The last part to remove, is the gear wheel with shank.
This can be done only, when the drive sprocket has been removed before.
Now we are ready. The gearbox is empty now.
Before starting the assembling of the gearbox, you should get an idea of the function of the gear controller.
The mainpart of the function of the gearbox is the right assembling of the gear controller.
The gear controller is basically made of three important parts:
Top: The routing for the two sliders.
Middle: The gearwheel, for turning the gear controller.
Bottom: The cavitys where the latch slips into, to hold the gear in position.
Usually, the gearbox will be mounted in nutreal gear.
For this we have a look at the lower part of the gear controller, where the latch slips into.
Here we will find five cavitys in different distances.
Each cavity stands for one gear plus nutreal gear.
If you look from the top onto the gear controller, and search for the widest distance of the cavitys (on the left side of the picture), the cavitys stands for the following order of the gears (anticlockwise):
1. Gear: First cavity after widest distance.
Neutral: Second cavity after widest distance.
2. Gear: Third cavity after widest distance.
3. Gear: Fourth cavity after widest distance.
4. Gear: Fifth cavity after widest distance.
To assemble the gearbox in nutreal gear, the latch has to go into the second cavity after the widest part.
On the parted geaerwheel is a mark, near the third tooth from left.
The tooth above the mark has to go in the cavity, which is above between neutral and 2. gear.
On the bottom of the motor housing is a screw, which holds the spring for the latch.
I turnd the screw as far as possible out of the housing.
This makes it later easier, to fit the gear controller.
The pictures always shows the gearbox, before the step has done
At first we fit the gear wheel with shank.
The latch and the sping for the latch has to be placed now.
The gear controller and the parted geaerwheel has to be fitted together.
For this see description about the position of controller - latch - gearwheel before.
The auxiliary shaft comes at next.
Now we place the spring and springsupport disc.
The slider and the gearwheel with 18 tooth can be fitted now.
The gearwheel comes on the auxiliary shaft, the slider into the spring.
When you do this, take care about the position of the slider in the gear controller. It has to fit into the lower routing.
Now the second slider and the gearwheel with 21 tooth will be placed in the same manner.
The gearwheel on the auxiliary shaft, the slider in the gear controller.
Again take care about the position of the sliders into the routing of the gear controller.
Insert the shifter shaft through the sliders, spring and springsupport disc.
The two gear wheels (bottom 21, top 18 tooth), which were placed on the main shaft, comes in place now.
The main shaft has to be insertet through the gearwheels now.
The last part inside the gearbox is the big gearwheel with 21 tooth on the auxiliary shaft.
Now we have all the parts in place and it is possible to test the gearbox.
As long as the screw at the bottom of the gearbox is not tighten, it is possible to turn the gear controller.
Because we have assembled the gearbox in nutreal gear, the drive sprocket must not turn (holden by hand), when you turn the main shaft.
If you turn the gear controller anticlockwise for one position of the latch, the first gear is engaged.
When turning the gear controller, you may have to support the sliders a little by hand, due the open haousing an the only on one side guided shafts.
In this way it is possible to check all the gears. To do this, you have to turn the gearcontroller clockwise.
When the gearbox is working, you have to tighten the screw for the spring on the bottom of the housing at last.
