Today, while fishing, my 2004 F150 experienced a major malfunction. The crankshaft snapped right under the flywheel. I stated the motor, slowly approached planning speed…normal as could be. I started to let off the throttle and I heard a severe rattle/clanking. I shut off the motor and decided I needed to figure out how I was going to get back to the ramp. I started the motor right back up. I started idling towards the cove with the ramp and the noise was horrible. but….the noise vanished above idle speeds …so off I went. When I started the boat again, to trailer it up, it again sounded really bad and normal above idle. I noticed that the water pressure was above 30 psi. No oil lights…nothing abnormal other than the noises at idle.
once on the trailer, I removed the cowling and the plastic engine trim and saw the flywheel was wobbly loose. Scary loose. But the end of the crankshaft was still very tight to the flywheel. Upon further inspection, I realized the end of the crankshaft had snapped(I’m assuming). What was holding the flywheel to the top of the motor I’m still not sure of. Even more impressive is the flywheel still has enough rotational “grip” on the rest of the crank to allow the starter to start the motor.
is there something else that could be wrong? I looked at the exploded view on SIM and it shows that the threaded end of the crank is one piece with the rest of the crank. If the threaded end is still very firmly attached with the nut on the flywheel, and the threaded end wiggles with the flywheel, doesn’t the crank HAVE TO BE BROKEN?
anyways. Guess I’m motor shopping. I don’t want to invest several thousand dollars to repair the motor and have a 19 year old lower unit, fuel system, etc. SAD! it still runs so smoothly. And very strong for a 150.