How tight should the prop nut be?

[Froeman]

I replaced the prop on my 2008 Larson 180 with Volvo 3.0 with SX drive (21p 3blade to 20p 4blade). Bought a Michigan wheel prop with hub kit that came with new washers etc. when I first installed I didn't think there was any "play" (front to back) but now there appears to be some, barely even a millimeter, just enough to move it. Should the nut be tight such that there is zero play? Do they "set in" after some boating? I could have sworn the not was fairly tight when I first installed it. FYI, bot seems to perform perfectly.

Thanks

 

[Texasmark]

Re: How tight should the prop nut be?

My service manual for a 90 hp says 55 ft-lbs. So you should be somewhere around there. Yes it should be tight and the reason is that every time you shift you will bang metal on metal which over time will wear the brass hub away and it will keep getting worse.

Mark

 

[Slip Away]

Re: How tight should the prop nut be?

No torque specs really, just get it as tight as you can. And make sure you greased the shaft before installing your prop, so it comes off easily when needed.

 

[DougGreer]

Re: How tight should the prop nut be?

I Think if you look on the box the hub kit came in, It will say to tighten to 55 ft. Ibs. and recheck after a few hours running.

 

[Texasmark]

Re: How tight should the prop nut be?

No torque specs really, just get it as tight as you can. And make sure you greased the shaft before installing your prop, so it comes off easily when needed.

Really. I have the capability of putting more than 250 ft-lbs of torque on farm equipment bolts. To follow your advice I could rip the threads out of the nut and/or the SS prop shaft, or buckle the brass splined prop adapter.

There are specs for it, just like there are specs for mine.

Mark

 

[joelybob]

Re: How tight should the prop nut be?

Really. I have the capability of putting more than 250 ft-lbs of torque on farm equipment bolts. To follow your advice I could rip the threads out of the nut and/or the SS prop shaft, or buckle the brass splined prop adapter.

There are specs for it, just like there are specs for mine.

Mark

some things you have to use your head when doing

 

[Outsider]

Re: How tight should the prop nut be?

Uhhh, sounds like a question for Volvo. The manufacturer of the drive (there's only one) determines the torque specs, there could be any number of propeller makers ...

 

[Knymc]

Re: How tight should the prop nut be?

Just replaced my prop on my 3.0 L with alpha one and it is 55 ft lbs. if your pushing/ pulling on prop should be very little amount of play. About the amount you mentioned. That is the shaft moving in and out, not the prop.

 

[Texasmark]

Re: How tight should the prop nut be?

Just replaced my prop on my 3.0 L with alpha one and it is 55 ft lbs. if your pushing/ pulling on prop should be very little amount of play. About the amount you mentioned. That is the shaft moving in and out, not the prop.

Pushing and pulling is not proper torque of the prop nut. In pushing and pulling, the prop and prop shaft move in and out in unison!!!!!!!! Pushing and pulling is working the overrun clutch which is part of forward gear and is used to allow the engine to decelerate while the prop is still spinning faster...like coming off plane. It's just like old Ford farm tractors. Without an overrun clutch, if you have a mower attached, the mower will propel the tractor forward till the mower stops....through fences, over hills, and dales, and all that, regardless of what you try to do with the clutch and the gear shift.

Over run clutch check is: Regardless of gear, engine off, just grasp the prop, properly installed on the shaft, and push it forward. It will move forward roughly 1/8", give or take. That is normal. If worried, go to a dealer with new engine/outdrives on the lot and do the same thing. It will put your mind at ease.

Need more, ask.

Mark

 

[avantifishski]

Re: How tight should the prop nut be?

so 55lbs of torque is suppose to line up the cotter pin? don't seem logical to my castlenut does yours line up?

 

[robert graham]

Re: How tight should the prop nut be?

Just good a darn tight, then a bit more enough to line up the cotter pin holes.....not gorilla tight, just good and tight....not brain surgery!..

 

[beason]

Re: How tight should the prop nut be?

Shop manual says 70-80 ft-lbs

 

[WIMUSKY]

Re: How tight should the prop nut be?

Say fellas, this thread is pushing a year old.....