Systems and methods for synchronizing shifting across marine propulsion devices

A propulsion system for a marine vessel, the propulsion system comprising:

• at least two marine propulsion devices each having a transmission;
• and
• a control system configured to:
• receive a signal to initiate shifting the transmissions;
• access, for each of the marine propulsion devices, a predetermined shifting time that represents an elapsed time between starting the shifting and completing the shifting;
• compare the predetermined shifting time for each of the transmissions to determine a longest shifting time;
• calculate, for each of the transmissions, an offset time that is a difference between the predetermined shifting time corresponding thereto and the longest shifting time;
• and
• in response to the signal to initial shifting, starting the shifting of each of the transmissions only after the offset time corresponding thereto has lapsed such that the transmissions complete the shifting at the same time.

A method for synchronizing shifting of first and second transmissions for first and second marine propulsion devices, respectively, the method comprising:

• receiving a signal to shift the first and second transmissions;
• identifying predetermined shifting times for the first and second transmissions, wherein the predetermined shifting times represent elapsed times between starting the shifting and completing the shifting of the first and second transmissions, respectively, and wherein the predetermined shifting times are provided as a function of engine RPM;
• comparing the predetermined shifting times to determine a longest shifting time;
• calculating, for the first and second transmissions, offset times that are a difference between the predetermined shifting times and the longest shifting time, respectively;
• sending separate signals to the first and second transmissions to start the shifting thereof;
• and
• separately starting the shifting of the first and second transmissions after the offset times corresponding thereto have lapsed, respectively.