Which shaft seal ? 25mm or 1" ? ( Volvo 25mm actual shaft size)

[vtomanov]

Does anyone know the actual Volvo-Penta 25mm shaft size is it 25mm or 1" ?

I'm really puzzled which dripless seal I need to buy - Orbitrade seems to sell two versions :

1. Orbitrade 91254-1 Stuffing box 25mm shaft 43mm stern tube

2. Orbitrade 91872-1 Stuffing Box Seal Kit for Volvo Penta 1"

Which one is my 25mm Volvo-Penta shaft ?

[a64pilot]

Take a mic to it, I say mic as opposed to caliper cause 1” is 25.4 mm, and .4 mm isn’t much different. So little that I wonder if it matters?

[jimbunyard]

Originally Posted by vtomanov

Does anyone know the actual Volvo-Penta 25mm shaft size is it 25mm or 1" ?

I'm really puzzled which dripless seal I need to buy - Orbitrade seems to sell two versions :

1. Orbitrade 91254-1 Stuffing box 25mm shaft 43mm stern tube

2. Orbitrade 91872-1 Stuffing Box Seal Kit for Volvo Penta 1"

Which one is my 25mm Volvo-Penta shaft ?

The 91254 appears to be without provisions to add cooling water and a bleed(?) orifice.

The 91872 has both.

The important dimensions are your actual shaft size and the stern tube OD;
they should all match.

As a64 suggests mike your shaft and get the appropriate one.

The .4 mm won't likely make a difference, but since it is tighter than 1", if you went with the metric on a 1" shaft, it might be prudent to get the one with the water cooling provision...

[hellosailor]

I would start by asking both parties (Orbitrade and Volvo) just how different the two parts are. I strongly suspect that if your shaft is identified by Volvo (as opposed to the PO or other source) as "25mm" that you would want the "25mm" part.

That measly 0.4mm difference in size may seem tiny to you, but obviously Orbitrade thinks there is a reason to have two of them. That's a difference of 15 mils (in Imperial speak) and that's about the same as four sheets of cheap copier paper. Measly, unless there are metal parts with clearances to be made.

[vtomanov]

Originally Posted by hellosailor

I would start by asking both parties (Orbitrade and Volvo) just how different the two parts are. I strongly suspect that if your shaft is identified by Volvo (as opposed to the PO or other source) as "25mm" that you would want the "25mm" part.

That measly 0.4mm difference in size may seem tiny to you, but obviously Orbitrade thinks there is a reason to have two of them. That's a difference of 15 mils (in Imperial speak) and that's about the same as four sheets of cheap copier paper. Measly, unless there are metal parts with clearances to be made.

That's my point also ... the o.4mm matters and I'm trying to understand why Orbitrade sell two different things with differnet ID numbers for Volvo 25mm and Volvo 1" shaft.

I'm inclined to think that Volvo as e Europe company will do metric things e.g. only 25mm shaft ... but seems Orbitrade thinks diffrently and especially sells 1" seal and asap supplies have it in stock in UK , vise verse no stock for the 25mm seal and need special order ... all seems very strange..

[Pete7]

I have a Volvo 2003 in a British yacht which has a 1 inch shaft and the prop taper is imperial 1:12. So they make both imperial and metric size seals for the French and German yachts.

For the sake of 30 seconds with a set of vernier calipers or mic why take a chance. You will also need to know this is if you have a shaft anode fitted.

Pete

[hellosailor]

Pete-
Volvo have done many things that are best explained by "Well, if we didn't put huge amounts of alcohol in the water cooler, it would have frozen over the winter."
A friend of mine had one of the very sturdy Volvo station wagons back in the early 80's. When the heater fan motor needed to be replaced, the procedure was something like "First, locate the marks on the firewall and cut out a 12" diameter plate". Honest, access it by cutting the firewall.
Now that they are owned by China, it becomes that case of a mystery wrapped in an enigma. Best to call them, then roll the dice.

[a64pilot]

Back in the late 70’s a friend of mine had a new Volvo station Wagon.
He called it the Swedish lady of the evening, just slightly different name I’m hesitant to post. So much money, so little pleasure.
It had all kinds of issues starting with the wheels leaking air, had to have them welded to stop it.
Finally one day after just sitting for hours, it burst into flames sitting beside of a Beechcraft King Air.

However is the shaft Volvo? I don’t think other engine manufacturers manufacture drive shafts do they?

[billknny]

Originally Posted by a64pilot

Back in the late 70’s a friend of mine had a new Volvo station Wagon.
He called it the Swedish lady of the evening, just slightly different name I’m hesitant to post. So much money, so little pleasure.
It had all kinds of issues starting with the wheels leaking air, had to have them welded to stop it.
Finally one day after just sitting for hours, it burst into flames sitting beside of a Beechcraft King Air.

However is the shaft Volvo? I don’t think other engine manufacturers manufacture drive shafts do they?

Exactly... the drive shaft is absolutely NOT made by Volvo, but is bolted on the back end of the transmission by the boat builder. You need to know the shaft size for picking a cutlass bearing, for shaft seals, prop and prop nut, etc. And that 0.4 mm DOES matter--well maybe not for shaft zincs, but for everything else...

So... you can ignore all the comments that refer to the shaft as a Volvo product. They don't know of which they speak.

I know it has been said over and over in this thread, but really... YOU NEED TO MEASURE IT! Or you can take the world of an anonymous internet geek with no skin in the game who gives you an answer you like....

[jimbunyard]

Originally Posted by vtomanov

That's my point also ... the o.4mm matters and I'm trying to understand why Orbitrade sell two different things with differnet ID numbers for Volvo 25mm and Volvo 1" shaft.

I'm inclined to think that Volvo as e Europe company will do metric things e.g. only 25mm shaft ... but seems Orbitrade thinks diffrently and especially sells 1" seal and asap supplies have it in stock in UK , vise verse no stock for the 25mm seal and need special order ... all seems very strange..

As noted, chances that Volvo put the shaft in your boat are virtually nil.

Orbitrade is an aftermarket supplier that handles non OEM Volvo parts, if you're familiar with Sierra in the US, they are analogues.

If for some reason you can't determine the size of your shaft but have the old seal asm, and there is Volvo part number on it, you can cross reference the Volvo number to the Orbitrade number. That of course doesn't mean you have the correct one for your shaft, only that you have one that replaces the Volvo seal you have now...

I was wrong about the cooling and grease fittings, the -1 suffix signifies if there is or is not a provision for them.

And regarding the .4 mm difference, it is of course best to get the right size, but given the way this particular seal is manufactured and used it may be possible that the two are interchangeable. The only source for that information is the manufacturer or their authorized representatives.

[sandy stone]

I own an older Beneteau with a Volvo 2003 engine and a 25 mm shaft. I absolutely guarantee that a 1" anode is not appropriate for a 25 mm shaft, and I doubt a 1" seal is either.

[senormechanico]

Maybe the part number 91254 means 25.4 as in 1 inch= 25.4 ?

[JOHNMARDALL]

A 25 mm shaft seal will not work satisfactorily on a 1" shaft and vice versa. You will need to mike the shaft and buy accordingly.

Good luck
John Mardall
Vetus Maxwell Group.

[CaptRickWeiler]

I have run into this before and the issue isn't so much the difference in shaft diameter but the taper at the prop. Metric shafts use a different angle for the taper then do the English sized shafts. I learned this the hard way! If you are changing out prop and shaft it's not as important, but still worth looking into.

[Mike Paget]

Hi check your shaft dia and stern tube if Radice make the appropriate which they did for my Westerly with a 25 mm shaft. I swapped my volvo one for a radice one it has a breather which needs a length of pipe long enough to reach above the water level outside the hull and also a grease hole so it never needs Burping and easy to apply grease.

Not pasted a link like this so hope it works, these seals are great.