Multi-speed transmission having automatic and manual modes

A transmission having a housing with a front wall and a rear wall, the transmission comprising:

• an input member adjacent the front wall;
• an output member adjacent the rear wall;
• first, second, third and fourth planetary gear sets each having first, second and third members, wherein the second planetary gearset is adjacent the front wall, the fourth planetary gear set is adjacent the rear wall, the third planetary gear set is located between the second planetary gear set and the fourth planetary gear set, and the first planetary gear set is located between the third planetary gear set and the fourth planetary gear set;
• a first interconnecting member continuously interconnecting the first member of the first planetary gear set with the first member of the fourth planetary gear set;
• a second interconnecting member continuously interconnecting the third member of the first planetary gear set with the first member of the second planetary gear set;
• a third interconnecting member continuously interconnecting the third member of the second planetary gear set with the first member of the third planetary gear set;
• a fourth interconnecting member continuously interconnecting the third member of the third planetary gear set with the second member of the fourth planetary gear set;
• and
• five torque transmitting mechanisms each selectively engageable to interconnect at least one of the first, second, and third members with at least one other of the first, second, third members, and a stationary element, and wherein the torque transmitting mechanisms are selectively engageable in combinations of at least three to establish at least eight forward speed ratios and at least one reverse speed ratio between the input member and the output member, and
• wherein the transmission is operable in one of an automatic mode and a manual mode, and
• wherein a first of the five torque-transmitting mechanisms is a selectable one-way clutch operable in each of a locked position and an unlocked position, the locked position prevents relative rotation between the third member of the fourth planetary gear set and the stationary member, and the unlocked position allows for relative rotation in a first rotary direction and prevents relative rotation in a second rotary direction between the third member of the fourth planetary gear set and the stationary member.

A transmission having a housing with a front wall and a rear wall, the transmission comprising:

• an input member adjacent the front wall;
• an output member adjacent the rear wall;
• first, second, third and fourth planetary gear sets each having first, second and third members, wherein the second planetary gearset is adjacent the front wall, the fourth planetary gear set is adjacent the rear wall, the third planetary gear set is located between the second planetary gear set and the fourth planetary gear set, and the first planetary gear set is located between the third planetary gear set and the fourth planetary gear set;
• a first interconnecting member continuously interconnecting the first member of the first planetary gear set with the first member of the fourth planetary gear set;
• a second interconnecting member continuously interconnecting the third member of the first planetary gear set with the first member of the second planetary gear set;
• a third interconnecting member continuously interconnecting the third member of the second planetary gear set with the first member of the third planetary gear set;
• a fourth interconnecting member continuously interconnecting the third member of the third planetary gear set with the second member of the fourth planetary gear set;
• a first torque-transmitting mechanism that is a selectable one-way clutch having a locked position and an unlocked position, wherein the selectable one-way clutch is engageable to interconnect the third member of the fourth planetary gear set with a stationary member;
• a second torque transmitting mechanism selectively engageable to interconnect the first member of the second planetary gear set with at least one of the third member of the second planetary gear set and the first member of the third planetary gear set;
• a third torque-transmitting mechanism selectively engageable to interconnect at least one of the second member of the first planetary gear set and the input member with at least one of the third member of the second planetary gear set and the first member of the third planetary gear set;
• a fourth torque-transmitting mechanism selectively engageable to interconnect the second member of the second planetary gear set with the second member of the third planetary gear set;
• a fifth torque-transmitting mechanism selectively engageable to interconnect at least one of the first member of the fourth planetary gear set and the first member of the first planetary gear set with the stationary element;
• wherein the torque transmitting mechanisms are selectively engageable in combinations of at least three to establish at least eight forward speed ratios and at least one reverse speed ratio between the input member and the output member, and
• wherein the locked position of the selectable one-way clutch prevents relative rotation between the third member of the fourth planetary gear set and the stationary member, and the unlocked position allows for relative rotation in a first rotary direction and prevents relative rotation in a second rotary direction between the third member of the fourth planetary gear set and the stationary member,
• wherein the transmission is operable in an automatic mode and a manual mode,
• wherein the locked position is selected when the transmission is operating in at least one of the automatic and manual modes and is engaged in the reverse speed ratio and when the transmission is operating in manual mode and the transmission is engaged in one of the first, second, third, fourth and fifth speed ratios, and
• wherein the unlocked position is selected when the transmission is operating in automatic mode and the transmission is engaged in one of the eight forward speed ratios.