View Full Version : Volvo AQ Prop shaft Cone Nut ?

08-02-2013, 12:36 AM
Does the original Volvo prop shaft streamlined cone nut really do very much to prevent turbulence and increase performance ?

Has anyone tried running, with & without the cone nut using a standard SS nylock prop retaining nut ?

With a modern Solas SS prop with a very large outside hub diameter I wonder if the cone retaining nut really does very much to stop turbulence ?

My old Volvo AQ 270 has a short shaft without a center drilled hole for a retaining capscrew.
I suppose I can always drill & tap the shaft center if necessary ?

I was thinking of just running with a SS nylock nut & possibly an extra thin jam-nut if the cone nut is really not necessary ?

Is the prop shaft's thread ~~~20 MM ?

Just Say N20
08-02-2013, 07:59 AM
You have too much free time. ;)

08-02-2013, 08:45 AM
I don't remember what size the threads on the prop shaft are but they are not metric.

Drilling and tapping the shaft for the retainer bolt is easy and has been detailed several times. That's not metric either...


08-02-2013, 03:56 PM
The cone does nothing but look nice, no hydrodynamics after the prop!

08-02-2013, 08:20 PM
You have too much free time. ;)

Yes~~I suspect you are possibly correct ?

Just thought drilling the center of that short splined shaft for the cone nut's retaining capscrew might overly weaken that old SS splined Volvo 270 prop shaft.

A few years back a neighbor had an old Volvo 280 AQ with a new aftermarket conversion Mercruiser prop hub spline adaptor prop shaft snap in half~ and he lost his new expensive prop.
I also heard that these aftermarket Merc spline style Volvo AQ propshafts also bent very easily.
I suspect a heat treating hardness, or an incorrect SS alloy issue issue ?

These aftermarket spline conversion shafts were sold to allow the use of Mercruiser style spline hubed propellers , that were easily available, on the old Volvo 250, 270, 280, & 290 Aquamatics. Few new high-pitch/speed Volvo splined hub props could be found at that time.
Solas had yet to make a new "Titan SS" Volvo AQ prop~~~
Until Big Grizz Randy urged them to enter this old Volvo Aquamatic outdrive prop market.

I do not see these aftermarket Merc adaptor shafts sold on the market anymore.

No small wonder ?

Ralph Savarese
08-12-2013, 06:49 PM
If I Remember correctly it is a 9/16 thread