The Volvo I-Shift is an automated manual transmission developed by Volvo subsidiary Volvo Powertrain AB for Volvo Trucks and Volvo Buses , with 12 forward gears and 4 reverse gears. It became available for trucks in 2001 and later buses in 2004.
15-535: Technically the I-Shift is an unsynchronised parallel-shaft gearbox , with an electronic control unit , responsible for operating the pneumatic system that handles the clutch and shifts. It constantly receives information about vehicle speed, acceleration, weight, road grade, torque demand and more, and can adjust revs and engine brake effect, the main shaft speed plate is responsible for the transmission speed and revs per particular gear in motion in correspondence with
30-499: A single-speed transmission and belt-drive to power the rear wheels. In 1891, the French Panhard et Levassor automobile used a three-speed manual transmission and is considered to have set the template for multi-speed manual transmissions in motor vehicles. This transmission used a sliding-gear design without any form of speed synchronization, causing frequent grinding of the gear teeth during gear shifts. The Panhard design
45-608: A type of non-synchronous (unsynchronized) manual transmission, where gear ratios must be selected in succession (order), hence direct access to a specific gear ratio is not possible. Most manual transmissions in modern passenger vehicles are fitted with synchromesh to equalize the shaft speeds within the transmission, so they are synchronous transmissions. All automatic transmissions have synchronizing mechanisms, and semi-automatic transmissions that use dog clutches typically have cone-and-collar synchronizing mechanisms. Massey Ferguson 135 The Massey Ferguson 135 (MF135)
60-481: The Euro VI version. In June 2014, Volvo Trucks presented a new dual-clutch version of the I-Shift, known as SPO2812, with overdrive and a maximum torque of 2800 N·m . The dual-clutch version is only available for trucks up to 540 hp. The I-Shift Dual Clutch has two input shafts which are alternatively connected to the engine through two clutches. When driving, the first gear is engaged by one input shaft while
75-443: The I-Shift are named AT (Automatic Transmission) or ATO, where the O stands for overdrive . The standard versions have a gear ratio of 1:1, while the overdrive has a ratio of 0.78:1, suitable for long-distance use. The numbers show maximum torque in hundreds of newton metres , plus 12 for the number of gears. The last part of the name is a letter showing its generation, with C for Euro III and IV, D for Euro V and EEV, and E and F for
90-508: The clutch brake will prevent the transmission from being shifted into or out of gear. Any transmission that requires the driver to manually synchronize the engine speed with the speed of the driveshaft is non-synchronous. Non-synchronous transmissions are mostly used in semi-trucks, large industrial machines, older agricultural tractors (e. g. Massey Ferguson 135 ) and power take-offs . Sequential manual transmissions , which are commonly used in motorcycles , ATVs , and racecars , are
105-424: The driver may have to complete 24 or more gear changes when accelerating from a standstill to 70 mph (110 km/h). Unlike any other type of transmission, non-synchronous transmissions often have a clutch brake mechanism, which is usually activated by pressing the clutch pedal all the way to the floor or pressing a button on the top of the gear lever. The purpose of the clutch brake is to slow down (or stop)
120-557: The driver to manually synchronize the transmission's input speed (engine RPM) and output speed (driveshaft speed). Non-synchronous transmissions are found primarily in various types of industrial machinery ; such as tractors and semi-tractors . Non-synchronous manual transmissions are also found on motorcycles , in the form of constant-mesh sequential manual transmissions . Prior to the 1950s and 1960s, most cars used constant-mesh (and also sliding-mesh) but non-synchronous transmissions. Most early automobiles were rear-engined, using
135-404: The first one has a low crawler gear with a 19.38 to 1 ratio and the second one has an ultra low crawler gear with a 32.04 to 1 ratio, they also enable to drive as slowly as 0.5 km/h. Non-synchronous transmission A non-synchronous transmission , also called a crash gearbox , is a form of manual transmission based on gears that do not use synchronizing mechanisms . They require
150-456: The gear file on ECU. The I-Shift uses different software for different type of application. The I-Shift has no clutch pedal. It is controlled either by a gearstick mounted on the driver's seat or by buttons on the dashboard, just like a standard automatic gearbox. With the gearstick, the driver can use buttons to manually select gear, although this feature is disabled on some vehicles (where the gearstick has no buttons). The different versions of
165-515: The main reasons being its simple mechanical construction and high reliability, as well as familiarity with the model from farmers' experiences studying at British agricultural colleges. The MF135 was most commonly fitted with a 45hp 2.5L Perkins AD3.152 3-cylinder diesel engine. Alternatives included the Perkins AG3.152 petrol variant, or a 37hp 4-cylinder Continental petrol engine in the US. It
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#1732802270212180-575: The other one pre-selects the next gear. At the actual gear change, the previously engaged clutch is disengaged as the idling clutch is engaged at the same time. This results in a Powershift and seamless transfer of power. In 2016, Volvo launched a new member of the I-Shift family, the I-Shift with Crawler Gears. The new gears, which are added to the automated transmission, provides exceptional startability for trucks carrying heavy loads and can start from standstill for up to 325 tonnes of GVW. The I-Shift with Crawler Gears adds 1 or 2 Crawler Gears as optional,
195-417: The rotation of the transmission's input shaft, which assists in shifting the transmission into neutral or first gear when the vehicle is at a standstill. The clutch brake not only slows or stops the idle gear axis but can also prevent shifting into gear until the clutch pedal is released a few centimetres (or inches) off the floor. In order to shift into gear, the clutch must be halfway off the floor, otherwise,
210-609: Was a tractor produced by Massey Ferguson . The MF135 was the first of the MF100 range, and was a successor to the MF35 . Production began in 1964 and ended in 1975, when it was succeeded by the MF235 . Several hundred thousand were produced, and along with the sister MF165 , were the most popular tractors of the era. The tractor is still sought after in the 21st century in the second-hand market due to demand in developing countries, one of
225-425: Was refined over the years by other manufacturers to include "constant-mesh" gears (instead of sliding gears). The first usage of synchromesh was by Cadillac in 1928. Trained drivers of vehicles with non-synchronous transmissions sometimes use the techniques listed below. If improperly implemented, these techniques can cause damage to the vehicle or the loss of control of the vehicle. In big rigs and semi-trucks,
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