Seal on propshaft keeps the oil IN the gearbox!

[Ian Malcolm]

I've been running my seagull with a V12A face lip seal replacing the standard seagull rubber washer 'Seal' for the last 5 years or so. The box still runs wet as I have made no attempt to add a seal above the pinion bearing, but the oil stays much thicker with far less water in it and there is very little if any leakage with the engine upright. The 10 hour oil level and quality check interval can be safely doubled at least, and you will usually only need to look, not fill.

Fit the seal to the propshaft between the brass collar on the shaft the prop rests on and the bearing at the rear of the gearbox with the lip towards the bearing. It turns with the shaft and uses the rear face of the bearing as the sealing surface.


Available from RS components http://uk.rs-online.com/web/search/sear ... hTerm=v12a or any good engineering seals and bearing speciality supplier.

Original thread mentioning the seal back in 2006 here.

[rosbullterier]

You'll be using EP 75 now then . . .

[Ian Malcolm]

No as I invested in 5L of SAE140 from Castrol classic oils the year before. Still got plenty left and I am not racing so no point in going to a lighter oil.

If I wanted to run a modern light gear oil, I'd think about fitting a seal on the driveshaft as well.

[Collector Inspector]

Keeping oil "In" seems a good idea, far less messy eh?

Britannia had a different slant in "Keeping the water out"......

The lip and stainless spring faced outwards.



Most of Australian Old Dears had that idea as well.

Food for thought eh?

B

[Ian Malcolm]

Well the lip on the V seal is angled outwards so it is effectively resisting external water pressure. Look at the PDF datasheet on the RS page linked to. Whether it would be more effective to run a seal with an inwards lip or an outwards one depends on the relative pressure below the water pump impeller and between the gearbox and prop. I suspect the lip is the wrong way for best results but it has cured the yellow drool from the back of the gearbox and is a long-term success that is invisible unless you tear down the foot and requires no permanent modifications so the historic purists should have little to bitch about.