I saw a brand new ’69 plate car reversing today and it still made that noise so it can’t be attributed to an old gearbox
In: Engineering
In addition to what the others have said, the reason that reverse gears are straight cut is that they have to slide past each other in order to engage reverse. This is not possible with herringbone or helical gears. The forward gears are constantly meshed so don’t need to slide past each other.
Most cogs in cars’ gearboxes mesh together with >>> patterns (helical cut or constant mesh) as it is quieter than straight cut gears III. Actually Citroen’s logo looks this way >> as this type of gear was invented by someone at the company. Reverse gears however are usually straight-cut as they take up less space and are much more simple gears. Reverse gears aren’t used as much as the rest of the gears so it is a good compromise.
Straight cut gears are strong however and in applications where being quiet is not so important (heavy machinery and rally cars) you hear whiny gears.
The gears are cut differently. Forward gears are used more, and so they’re cut helically. This makes their engagement smoother and the gears last longer. The reverse gear, since it is used less, has straight cut gears. These are cheaper, but add that whine.
Latest Answers