Mercury Outboard 8M0123581 Steering Cylinder Actuator JPO Gen 2
Important replacement part information belowThis is a genuine Mercury Marine factory OEM part, not aftermarket
Please see important information below. Use the Contact Us form at the bottom of the page for any questions
Mercury Marine 8M0123581 Power Steering Cylinder Actuator Joystick Piloting Outboard (JPO)
JPO Systems with Design 1 Helm Components:
On Gen 1 JPO systems with Design 1 helm components (see below), if one steering cylinder needs replacement, it is recommended that all of the steering cylinders on the boat be replaced with Gen 2 cylinders.
IMPORTANT: The Gen 2 steering cylinder responds differently than the Gen 1 steering cylinder, and the Design 1 software cannot compensate for the variance. The Gen 2 steering cylinder will respond to steering and joystick commands faster than the Gen 1 cylinder, which will cause a noticeable visual difference in the turning rates of the engines.
On JPO Systems with Design 2 Helm Components:
On Gen 1 JPO systems with Design 2 helm components, an individual Gen 1 steering cylinder can be replaced with a Gen 2 steering cylinder. This will require a reflash of the TVM software with CDS G3 by a Mercury dealer for proper operation.
It is acceptable to have Gen 1 and Gen 2 steering cylinders installed together on the same boat with Design 2 helm components. The service TVM calibration will make the operation of the different steering cylinders the same.
IMPORTANT: If the TVM that is controlling the Gen 2 steering cylinder is not reflashed, steering performance will not be the same between the new and old steering cylinders. This could lead to boat handling issues.
If the tie bar arm is removed during steering cylinder replacement, the fasteners that connect it to the engine must be replaced.
A current sensor must be installed on the power steering pump power cable regardless of which style of pump is installed. IMPORTANT: If a power steering pump current sensor is not installed, damage to the steering cylinder will result if the pump shuts down undetected. Please see related items below to order a new sensor diagnostic kit.
NOTE: When replacing a Gen 1 steering cylinder with a Gen 2 cylinder, the hydraulic hose connections are different. Remove the fittings from the Gen 1 steering cylinder and install them into the Gen 2 steering cylinder.
Parts per engine for the L6 Verado serial #2B144122 and below are here:
Qty | Desc | Part # |
2 | Screw 8 mm | 896555025 |
2 | Tab washer | 896634 |
Parts per engine for the Verado serial #2B144123 and above and ALL Verado V8's are here:
Qty | Desc | Part # |
1 | Hardware kit | 8M0099091 |
Mercury Marine 8M0123581 Power Steering Cylinder Actuator Joystick Piloting Outboard (JPO)
JPO Systems with Design 1 Helm Components:
On Gen 1 JPO systems with Design 1 helm components (see below), if one steering cylinder needs replacement, it is recommended that all of the steering cylinders on the boat be replaced with Gen 2 cylinders.
IMPORTANT: The Gen 2 steering cylinder responds differently than the Gen 1 steering cylinder, and the Design 1 software cannot compensate for the variance. The Gen 2 steering cylinder will respond to steering and joystick commands faster than the Gen 1 cylinder, which will cause a noticeable visual difference in the turning rates of the engines.
On JPO Systems with Design 2 Helm Components:
On Gen 1 JPO systems with Design 2 helm components, an individual Gen 1 steering cylinder can be replaced with a Gen 2 steering cylinder. This will require a reflash of the TVM software with CDS G3 by a Mercury dealer for proper operation.
It is acceptable to have Gen 1 and Gen 2 steering cylinders installed together on the same boat with Design 2 helm components. The service TVM calibration will make the operation of the different steering cylinders the same.
IMPORTANT: If the TVM that is controlling the Gen 2 steering cylinder is not reflashed, steering performance will not be the same between the new and old steering cylinders. This could lead to boat handling issues.
If the tie bar arm is removed during steering cylinder replacement, the fasteners that connect it to the engine must be replaced.
A current sensor must be installed on the power steering pump power cable regardless of which style of pump is installed. IMPORTANT: If a power steering pump current sensor is not installed, damage to the steering cylinder will result if the pump shuts down undetected. Please see related items below to order a new sensor diagnostic kit.
NOTE: When replacing a Gen 1 steering cylinder with a Gen 2 cylinder, the hydraulic hose connections are different. Remove the fittings from the Gen 1 steering cylinder and install them into the Gen 2 steering cylinder.
Parts per engine for the L6 Verado serial #2B144122 and below are here:
Qty | Desc | Part # |
2 | Screw 8 mm | 896555025 |
2 | Tab washer | 896634 |
Parts per engine for the Verado serial #2B144123 and above and ALL Verado V8's are here:
Qty | Desc | Part # |
1 | Hardware kit | 8M0099091 |