One of the few components in the vehicle that can be badly damaged by incorrect handling is the synchronisation of the gear box. Tugging the gear lever
too fiercely, particularly
when downshifting, forces a fast constant velocity of the friction areas, leading to undue wear and tear. The car manufacturers, in their attempts to achieve a certain amount of long service life for as many components
as possible, have introduced improvements for the 1st to 3rd gears.
How it works
The synchronisation should bring, as the name says, the synchronizer with sliding clutch (far right) and the gear wheel (far left) to the same RPMs and only then allow them to mesh with each other. All components
shown above have bevelled surfaces. As long as no synchronisation is reached, the overlapping of the sliding clutch onto the pre-gearing is blocked by another geared rim in the second synchronising ring. Starting
point of the double synchronisation is a gear wheel with pre-gearing. The diameter is considerably larger than that of the friction cone. This way, space is created for the first synchronising ring with two friction surfaces
and a washer with also two friction surfaces. The following, second synchronising ring is almost unchanged. It fits, with its three (red) gaps, in such a way, into the synchronizer that it can only misconnect by a half a
cog in either direction.
The non-slip (blue) connection between the gear wheel and the washer is important for the effect of the three friction surfaces. At the same time through (green) claws, both synchronising rings are also connected with
each other. Thus the Synchronisation facility works like a multiple-disc oil bath clutch. From a logical point of view, more than two synchronising rings are possible. 09/08