A simple box is made up of a shell or case, shafts and sprockets (axles). Overlooking the structure of the gears slipping on the axes, we can say that in the fixed clutch boxes there are two large axles, the primary that transfers the torque from the clutch and has a fixed gear (input) with the same rpm as the crankshaft. The secondary is in parallel and is permanently engaged with the primary when the driver does not clutch.
More specifically, the gears are permanently locked together in pairs and turn freely on their shaft ("crazy") until the intermediate engagement gear (collar, connecting ring) locks the movement sliding on the minor axis. Each time the driver moves the lever, the corresponding knob moves and thus the gears are not engaged directly but through the knobs for smoother and silent operation. The above are fixed coupling boxes.
Robotics
- Advantages: do not burden consumption, low manufacturing costs, reliability
- Disadvantages: relatively slow change in relationships, knocking on change
Here is an automated clutch where the gear changes are made by means of an electric motor that activates the clutch. In addition to the clutch actuator, the electro-hydraulic system also includes one for changing the gears / ratios. Simply put, the pressing of the clutch pedal (which does not exist) is assumed by an electric motor as well as changing the ratios, which instead of being manually performed, is re-performed electro-hydraulically.
So every time the driver chooses the serial program (instead of the automatic D option), a sensor perceives the movement of the the selector {usually up and down with hints (+) for ups and (-) for downloads} e.g. from 2a. Then the electronics unit commands a reduction in engine rpm, the clutch opens, the actuator changes e.g. in 3rd gear and the clutch re-closes to transfer torque. Of course, when the car tends to stop or when the ABS intervenes, it automatically fades.
Classic
- Advantages: automatic change of relationships, reliability, absence of drives and overheating
- Disadvantages: increased consumption and weight, bulky in dimensions
Transmission is carried out by the hydraulic torque converter acting as a clutch transferring power from the engine to the gearbox. An essential part is the ATF (Automatic Transmission Fluid), the planetary transmission system and the interlocking and electronic management unit.
Unlike the manual gearbox, in the automatic gearboxes parts of gear are not used between the two axles, but planetary devices (usually 2-3) are combined with each other, resulting in the gear ratio between the crankshaft and the output to the differential. The configuration of the combination is carried out with the belt, something like a "brake" that is hydraulically actuated and adjusts the position of the devices. Almost every modern box has a "serial" function (it allows manual only successive relational changes) while there are various programs depending on the driving conditions (comfort, sport, economy, etc.).
CVT Boxes
- Advantages: simple to build, good for consumption, smooth change of relationships, cost, compactness in dimensions
- Disadvantage: a patinating phenomenon, not so fast, limited power transfer to the limit
These are gearboxes not composed of gears but of a belt system with two pulleys. In hybrids, it is customary to use a planetary fit CVT to combine the MEK motion with the electric motor.
A transmission service is part of your routine maintenance, just like replacing your engine oil.
service
A complete transmission service should include:
- removing and examining the sump or pan (where possible)
- replacing or cleaning the screen or filter
- cleaning the pan
- reinstalling the pan with a new pan gasket
- pumping out the rest of the old fluid and replacing it with new, high quality ATF
- adding a friction modifier or additive package (model specific)
New fluid restores the holding power between the clutches, reducing slip and heat production.
At the same time, flushing the old fluid washes away tiny particles of clutch material and metal shavings. Those particles clog passages and wedge between moving parts, and thus they cause wear throughout the transmission. Changing the fluid eliminates those particles and the wear they cause.
The net result of changing the fluid is to provide better lubrication, improvement of the holding ability of the friction components, and truction of heat. So your transmission works better for years longer, which means you’re less likely to face a major transmission repair.
And, where possible, adding an external filter to the cooler line to remove any dirt particles that make it past the internal filter. Most ATRA Member shops offer a complete fluid exchange service, and will be happy to explain the details to you.
Manual transmission fluid is one of the most overlooked maintenance items and is usually one of the simpler, more economical services. It usually consists draining the fluid, flushing & refilling. Inspecting for abnormal debris from internal failure and moisture due to condensation are an important step. The cost of the service will fluctuate depending on recommended fluid type, however most manual transmissions usually hold no more than 4 quarts.
In addition to our regular differential service, we also offer replacing your fluids with Royal Purple, a fully synthetic gear oil. This synthetic oil is designed to resist thermal breakdown better than most regular manufacturer used lubricants. Synthetic oils have Teflon additives which allow the oils to stick better to metal internals, reducing the risk of metal fatigue.
Technical - Transmission