Exam 21: Continuously Variable Transmissions

Technician A say the most common type of continuously variable transmission (CVT) today is the variable-diameter pulley transmission. Technician B says the variable-diameter pulley (VDP) transmission has two pulleys that are in direct contact with each other. Who is correct?

Which of the following is most likely an overdrive gear ratio for a variable-diameter pulley (VDP) system?

Technician A says some manufacturers have programmed into the power train control module (PCM) regular shift points for their continuously variable transmission (CVT), at which the pulley sheaves will move to predetermined positions to create the feel of separate conventional shifts. Technician B says some manufacturers allow the driver to manually shift through these predetermined pulley diameters while driving the vehicle. Who is correct?

Technician A says continuous variable transmissions may use two variable diameter pulleys rather than gears to change ratio. Technician B says a hybrid vehicle may use a parallel hybrid transmission, in which either the engine or an electric motor can power the transmission. Which technician is correct?

Which of the following is not a type of continuously variable transmissions (CVT) used in production vehicles?

Tech A states that when replacing a CVT belt the sheaves should be checked for wear. Tech B states that the bearings might require replacement when replacing the belt. Who is correct?

Technician A says that some Continuously Variable Transmissions (CVT's) require a heating system to warm the transmission fluid during cold weather operation. Technician B says that CVT's are able to create an infinite number of gear ratios between their minimum and maximum ratio. Who is correct?

Technician A says the toroidal continuously variable transmission (CVT) is limited in production because of high manufacturing cost. Technician B says the toroidal, or roller, design uses four curved discs - two input discs and two output discs. Who is correct?

Technician A says that some Continuously Variable Transmissions (CVT's) require a heating system to warm the transmission fluid during cold weather operation. Technician B says that CVT's are able to create an infinite number of gear ratios between their minimum and maximum ratio. Who is correct?

Technician A says a variable-diameter pulley (VDP) system operates using two variable diameter pulleys with either a steel or a rubber belt between them. Technician B says the rubber belt has a limited service life in an automobile, so most manufacturers use them. Who is correct?

Technician A says that a belt can fall apart during installation, requiring a time-consuming process to reassemble. Technician B says that if the belt is damaged during assembly, it is ok to use as it is new. Who is correct?

All of the following statements are true with respect to belt service except:

Technician A says the steel belt used in a variable diameter pulley continuously variable transmission (CVT) is made up of hundreds of transversely mounted steel plates that are held in place with several steel bands. Technician B says the transverse steel plates slip on the sides of the pulley and in turn are pulled by the pulley. Who is correct?

Tech A states that special tools will be required to replace the belt in a CVT. Tech B states that CVT belts can be rebuilt by specialty shops. Who is correct?

Which of the following ratios is the maximum overdrive between the pulleys of a variable-diameter pulley (VDP) transmission?

A CVT belt should be inspected for wear around the edges.

Tech A states that some CVTs offer a low range gear for extra torque when needed. Tech B states that many CVTs utilize a cogged rubber belt for the drive belt. Who is correct?

The CVT most commonly found in hybrid vehicles is known as:

The variable-diameter pulley CVT:

In a Continuously Variable Transmission (CVT), what changes in a smooth step-less progression to suit speed and load conditions.