wobbly prop

[bruce A.]

have a 2019 Mercury 50hp 4 stroke with less than 10 hours on motor. Changed lower unit lube today and it was very milky. Noticed that prop had a lot of front to back movement and side wobble, all movement is in the prop not the shaft. took prop off and can see where it has had metal to metal contact with lower unit housing. prop is not visually damaged. Read that the new Mercury props have a lot of play but this seems ridiculous especially with the metal to metal contact. could the hub be damaged even though Ive never hit anything?

 

[bruce A.]

the FloTorq Reflex hub as some fore and aft play as part of its design. I think this allowed the hub to back off from being fully seated and introduced a slight wobble. I hope this wobble didn't damage the shaft seal but since the gear lube was milky Im not holding my breath. Ordered a Michigan Wheel prop and hub kit and will check gear lube after a couple outings.

 

[Texasmark]

My 3 and 4 cylinder mid range Merc Service Manuals, indicate that the prop nut is to be tightened to 55 ft-lbs..........that doesn't sound like a sloppy fit to me. You are just asking for trouble.

Opinion: The only slop in a Merc Prop shaft is fore and aft about ⅛-¼" which is the "Over run Clutch" movement associated with F gear allowing the engine to decelerate faster than the prop when at speed and cutting the throttle to a slower speed.

You can put the shifter in F and rotate the prop CW and in watching the prop to LU casting spacing, see it move out and fall back....I call it a saw toothed pattern.

 

[QBhoy]

Quite likely you need to check if someone had forgotten to put the thrust washer spacer behind the prop.