OMC electric shift lower unit gearcase trouble shooting
Forward and reverse electrical clutch coil repairs
Forward or reverse coils
Forward or reverse springs
Outdrive coming out of gear
mixed in the oil
Water pump shaft splines stripped
Forward or reverse coils can be tested with ohm meter. They should read around 4 to 6 ohms. Ohm meter
reading can very. It is important that the reading of both coils be similar in range. To test coil, place one ohm meter probe
on green wire (forward coil), then second probe to ground or case. Repeat test step with blue wire (reverse coil).
Forward or reverse springs are best tested by applying 12 volts positive to the forward coil wire and the
black to ground. Propeller shaft will need to be locked in place with 5/16 pin or screwdriver going thru pin area. Turn vertical
drive shaft clockwise with torque wrench (set at 80 lbs.) Most broken springs will start to slip at less than 10 lbs. of torque.
Out-drive coming out of gear and engine revving high, can be caused by poor wire connections
or shift switch contacts are going. Old shifter switch contacts often work intermittent as contact area gets worn out, much
like the points of an engine. Note, if switch or wire temporary becomes open circuit and then closes starting engagement of
coil at high RPM 1000 to 4000, It could break the forward spring. Reverse spring is broken most often by going from forward
to reverse too fast, Thus not letting water drop rpm down on prop.
Water mixed in the oil ? The
most common is fishing line in the seals.
Water pump shaft splines stripped. This shaft will break
or seize up, if the upper drive shaft tapper bearing (located in the lower unit) is low on oil.
T.C. Electronics/Marine (416) 751-7326 Copyright 2002 to 2019 all rights reserved