An axle assembly having a drive pinion, a transmission, and a shift collar. The transmission may include a set of drive pinion gears. The shift collar may be rotatable about an axis with the drive pinion and may be moveable along the axis with respect to the drive pinion to selectively connect a member of the set of drive pinion gears to the drive pinion.

A shift device includes: a shift switching member including valley parts corresponding to a shift position; a positioning member provided to establish the shift position in a state of being fitted into any one of the valley parts; a motor including a rotor and a stator and driving the shift switching member; a speed reduction mechanism section rotating the shift switching member in a state in which a rotation speed transmitted from the motor is reduced; a rotor rotational angle sensor detecting a rotational angle of the rotor; and an output shaft rotational angle sensor detecting a rotational angle of the shift switching member A width of a backlash included in the speed reduction mechanism section is detected, and the rotational angle of the motor corresponding to the center of the backlash is acquired.

An automatic transmission where the control portion controls the adjustment solenoid valve so that the circulation hydraulic pressure equals to a second circulation hydraulic pressure higher than the first circulation hydraulic pressure when the rotational speed difference between the output rotational speed of the fluid transmission device and the rotational speed of the driving source is more than the predetermined rotational speed.

An adjuster mechanism and an axle assembly that includes an adjuster mechanism. The adjuster mechanism may include a collar assembly that has a collar that may receive a shift collar, a follower, and an adjustment screw. Rotating the adjustment screw may move the collar assembly and the shift collar along an axis.

An adjuster mechanism and an axle assembly that includes an adjuster mechanism. The adjuster mechanism may include a collar assembly that has a collar that may receive a shift collar, a follower, and an adjustment screw. Rotating the adjustment screw may move the collar assembly and the shift collar along an axis.

An axle assembly having a drive pinion, a transmission, and a shift collar. The transmission may include a set of drive pinion gears. The shift collar may be rotatable about an axis with the drive pinion and may be moveable along the axis with respect to the drive pinion to selectively connect a member of the set of drive pinion gears to the drive pinion.

A shift device includes: a shift switching member including valley parts corresponding to a shift position; a positioning member provided to establish the shift position in a state of being fitted into any one of the valley parts; a motor including a rotor and a stator and driving the shift switching member; a speed reduction mechanism section rotating the shift switching member in a state in which a rotation speed transmitted from the motor is reduced; a rotor rotational angle sensor detecting a rotational angle of the rotor; and an output shaft rotational angle sensor detecting a rotational angle of the shift switching member A width of a backlash included in the speed reduction mechanism section is detected, and the rotational angle of the motor corresponding to the center of the backlash is acquired.

The invention relates to a system (2) for controlling a disengageable hydraulic transmission (1) for a vehicle, involving the circulation and the pressurisation of a transmission fluid, said system (2) comprising: means (21) for collecting information relative to the operation of the hydraulic transmission (1) since the last time the transmission was serviced, means (22) for estimating an ageing state of the transmission fluid based on the information collected, and means (23) for controlling the disengageable hydraulic transmission (1) as a function of the estimated ageing state.

The invention relates to a system (2) for controlling a disengageable hydraulic transmission (1) for a vehicle, involving the circulation and the pressurisation of a transmission fluid, said system (2) comprising: means (21) for collecting information relative to the operation of the hydraulic transmission (1) since the last time the transmission was serviced, means (22) for estimating an ageing state of the transmission fluid based on the information collected, and means (23) for controlling the disengageable hydraulic transmission (1) as a function of the estimated ageing state.

An automatic transmission where the control portion controls the adjustment solenoid valve so that the circulation hydraulic pressure equals to a second circulation hydraulic pressure higher than the first circulation hydraulic pressure when the rotational speed difference between the output rotational speed of the fluid transmission device and the rotational speed of the driving source is more than the predetermined rotational speed.