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OMC Cobra Trim Sender

Trim Sending Unit for OMC Cobra Outdrives

  • Trim sending unit replaces OMC 984748, 385040 and Sierra 18-7634
  • Used to control the raising and lowering of the outdrive trim cylinders
  • 2 wire Sierra part with 2 year warranty
  • Compatible with 1986 - 1992 models (does not work with the King Cobra 460 model, or cone clutch model)

Trim Sender

P/N 18-7634 Cobra trim / tilt sending unit

OMC Cylinder Cobra Outdrive

OMC Cylinder Cobra Outdrive

Used trim cylinders
Call for availability

To remove the trim cylinders, begin by removing the plastic caps on the aft (drive) side, followed by the nuts and washers. Gently tap one side of the pivot rod while easing the cylinder off the rod. Repeat on the other side. Next, remove the rear nut (transom side) on each cylinder and pull of the cylinder covers. Remove the retainer, and then disconnect the aft (drive side) hydraulic line. Make sure to have a drain pan below the hoses to catch the fluid. If you have diagnosed the problem to be the trim cylinders, such as leaking oil seal around the rod or a damaged impact valve, it is recommended the cylinders be replaced. The reason for this is the end caps of the cylinders; even with a special tool are extremely difficult to remove to open up the cylinder.

Trim tilt wiring GM Chevy

There are many electrical components in the circuit for the tilt and trim system, including the main components such as the motor, battery and switch.

To test your trim sending unit, begin by working your way down - starting with the battery. Using a multimeter, check the tilt/trim breaker (50 amp) and the 10 amp pump breaker.

If these are not blown, disconnect your sending unit. Using your multimeter, checking for ohms, connect each lead to each of the sender's wires.

While moving the sender arm back and fourth, the ohm readings should show between 0 and 190-210 ohms. If they do not, you're sending is defective and needs to be replaced. This method of diagnosis can only be used for 1986 - 1992 models.