slop in prop

[chrisvr6]

I got a couple extra used props with my boat and decided to install one of them. Well the new one doesnt have the hub that slides out like the existing one and has a lot of front to rear play in it. Is this ok to run it like that?

 

[Texasmark]

Re: slop in prop

No. You probably have the wrong thrust washer for the older style without the removable hub since you said that the current prop had one. You want it to fit tight so that it doesn't flop around around when shifting from gear to gear.

The thrust washer goes on the prop shaft before the prop is installed.

Mark

 

[chrisvr6]

Re: slop in prop

Can I just use washers? How do you know which size brass to use?

 

[Texasmark]

Re: slop in prop

Can I just use washers? How do you know which size brass to use?

The one that gives you a tight fit. Most thrust washer inner diameters are tapered as are prop shafts. When installing one ensure that the tapers are in the direction that allows the washer to slide forward on the prop shaft till it jams. To give you an idea as to what I am talking about, my Merc manual for my 90 hp engine states that the prop nut needs to be torqued to 55 ft-lbs. That is tight; not gut wrenching tight, but a long ways from being loose....and this is for a prop with a rubber, permanently affixed hub.

Mark

 

[jestor68]

Re: slop in prop

Are we talking about taking off a Mercury prop with the Flo Torque hub and putting on a convention hub prop? Did you use the proper outer washer that goes on the prop before the prop nut? If you run out of threads on the prop shaft and things are not tight, you left something out.


Notice the outer washer is part of the hub assembly on the Flo-Torque. If you replace it with a conventional hub prop, you must supply the outer washer as a separate piece.

 

[chrisvr6]

Re: slop in prop

Ok, found another thrust washer in box that came with boat. Its the same thickness as the other. So, I was thinking to double up to move the prop backwards a little so I can thread the nut. I'm running out of thread with only one. The original had the spline insert which protruded a bit a let prop sit flush in housing. HELP!

 

[chrisvr6]

Re: slop in prop

Ok, test fit the two thrust washers back to back and it all lines up nice. It's just that the prop is backed off a bit and there is a gap between housing and prop. Is this cool?

 

[geoff-nz]

Re: slop in prop

No its probably not cool.

Assuming you have a Merc and a prop with a fixed rubber hub the order should be.........

Thrust washer
Prop
Toothed washer with internal splines
Tabbed washer to bend down to lock the nut into the toothed washer (if that makes sense)
Nylock nut.

If you have a gap between the housing and prop hub something is not right. The gap will allow exhaust gasses to flow outside the hub possibly causing ventilation or cavitation issues.

 

[Bondo]

Re: slop in prop

Ok, test fit the two thrust washers back to back and it all lines up nice. It's just that the prop is backed off a bit and there is a gap between housing and prop. Is this cool?

Ayuh,.... Ya need the proper hardware, as explained by geoff-nz, or yer gonna screw up yer motor...:facepalm: