Prop Play

waverunner · 24 February 2008, 20:01

My Humber 5.5mtr Destroyer is just about ready for her maiden voyage, however I have one slight hang up. I have a new laser 11 20" stainless prop fitted to a Mercury Optimax 115. The stepped brass washer has been fitted first, followed by the prop with the flo torque hub assembly, and finally secured with the tab washer and nut.

Everything has been fitted correctly and well tightened up, but there seems to be a little bit of end float and slight side play in the prop, I checked this against my mates prop and found he has some end float but no side play, and wondered if this is normal with the flo torque hub assembly.

Ian M · 24 February 2008, 20:11

I would get it checked out. I had similar play with the flo torq hub on a 2005 90 Optimax. Hub was knackered with very few hours on it!

waverunner · 24 February 2008, 20:13

It shouldn't be knackered everything is new!!

Limey Linda · 24 February 2008, 20:24

Quote:

Originally Posted by waverunner

It shouldn't be knackered everything is new!!

Something is wrong. I have just fitted a flowtorque Mirage prop. and just checked it. No side play. The stepped washer should have a tapered bore that matches the shaft so no side play is possible. Worth checking out.

waverunner · 24 February 2008, 20:53

I checked the tapered bore in the stepped washer and it fits fine, really good fit on the shaft. I can only think that when the nut is tightened its not fully pulling everything home for some reason. The side play is only slight but my thoughts are there should not be any play at all.

Limey Linda · 24 February 2008, 21:13

Quote:

Originally Posted by waverunner

I checked the tapered bore in the stepped washer and it fits fine, really good fit on the shaft. I can only think that when the nut is tightened its not fully pulling everything home for some reason. The side play is only slight but my thoughts are there should not be any play at all.

Your should have a castellated brass washer that goes behind the tab washer: it also has a step in it. make sure it is seated properly and thus allowing the nut to force the prop. and the rear tapered washer fully on to the shaft taper. The nut should hold the prop./rear washer hard onto the taper.

Hightower · 24 February 2008, 21:15

Nothing should move except for turning around

Are you sure it's not the prop shaft moving back and forth a little?

Limey Linda · 24 February 2008, 21:23

Quote:

Originally Posted by Hightower

Nothing should move except for turning around

Are you sure it's not the prop shaft moving back and forth a little?

Good point, if the prop. shaft itself is moving then the bearings are knackered. Is it a new engine?

waverunner · 24 February 2008, 21:51

Quote:

Originally Posted by Limey Linda

Good point, if the prop. shaft itself is moving then the bearings are knackered. Is it a new engine?

Its a new engine, with absolutely no play in the prop shaft. Its looking as though the brass castellated splined spacer that was supplied with the engine is too long. I will ,try a shorter one tommorow.

Paul F · 24 February 2008, 21:57

What have you torqued it up to? not that it would have a great deal of effect on it
Paul

Limey Linda · 24 February 2008, 22:10

Quote:

Originally Posted by waverunner

Its a new engine, with absolutely no play in the prop shaft. Its looking as though the brass castellated splined spacer that was supplied with the engine is too long. I will ,try a shorter one tommorow.

Best of luck. let us know the result.

waverunner · 24 February 2008, 22:11

I didn't get as far as torque-ing it up as it obviously isn't correct.

waverunner · 24 February 2008, 22:13

Quote:

Originally Posted by Limey Linda

Best of luck. let us know the result.

Sure will, and thanks.

rama · 24 February 2008, 23:06

You have the flo torq 111, hub as supplied with all 1.5l optis, these are designed to reduce prop rattle with stainless props,
they should have +- 10 degrees of rotation and between 0.7620mm and 3.1750mm of end play

waverunner · 25 February 2008, 19:05

Quote:

Originally Posted by rama

You have the flo torq 111, hub as supplied with all 1.5l optis, these are designed to reduce prop rattle with stainless props,
they should have +- 10 degrees of rotation and between 0.7620mm and 3.1750mm of end play

The brass castellated splined spacer supplied with the engine measures 118mm in total length which as you say this probably is a flo torq 111 hub, as supplied with all 1.5l optis, but unfortunately the brass castellated splined spacer is too long for the prop I have fitted, as it is noticeable that as I tighten the retaining nut it feels as though it comes to a sudden halt with a spanner as if the spacer has bottomed out before the prop becomes tight. When I removed the prop and inspected it you could see that the brass castellated splined spacer is about a couple of millimetres too long as it protrudes beyond the two piece plastic flo torque insert that also came with the engine. I have replaced this for one which measures 60mm total length from a flo torq 11 hub, and there is absolutely no play in the prop, and as it is tightened with the spanner you can feel it removes all the play in the prop. I have tightened the retaining nut to what feels right, but would be grateful if anyone could supply me with the correct torque value so I can check if it is set up correctly.

Thanks for the useful replies, I feel a lot happier with my prop set up, if I had ran the engine as it was it may have caused some damage.

Tony.

waverunner · 25 February 2008, 19:13

Found torque settings in the manual 75Nm or 55lb.ft.

Limey Linda · 25 February 2008, 19:25

Hi There
Don't worrry about torque as you are going to have to juggle it a bit so that the lock tabs line up. Snug it up lightly and check you have no wobble, then apply a little more torque until three of the six locking tabs line up. Tap the three tabs down only so they engage. Don't beat the hell out of them as you will curse when you need to take the prop. off.
Regards, Tony
Ps. glad it worked out.
PPS. I would feel a little uncomfortable about reducing from 118 mm to 60mm. I would take your long spacer to a machine shop and have them machine off 10mm.

waverunner · 25 February 2008, 20:18

Quote:

Originally Posted by Limey Linda

Hi There
PPS. I would feel a little uncomfortable about reducing from 118 mm to 60mm. I would take your long spacer to a machine shop and have them machine off 10mm.

That has already crossed my mind. It is better to spread the load of the prop against more spline surface area as possible and let the flo torque do its job. By going down to 60mm, actually probably less, more like 50mm due to the head of the castle nut not being splined, it has drastically reduced the physical drive or working area of the splines which could create wear on the prop shaft.

Limey Linda · 25 February 2008, 20:26

Quote:

Originally Posted by waverunner

That has already crossed my mind. It is better to spread the load of the prop against more spline surface area as possible and let the flo torque do its job. By going down to 60mm, actually probably less, more like 50mm due to the head of the castle nut not being splined, it has drastically reduced the physical drive or working area of the splines which could create wear on the prop shaft.

You got it. After time you may see a step in the splines and a twist in the hub sleeve as , as you say, you are only using 1/2 of it.