Draining the mayo out the gearbox

[Keith.P]

Yes.

[Merry]

Ok I got the bush off, and that tiny slither of rubber is the grommet, also there is some serious roughness behind it, kind of looks to me like an edge has broken away, or is it bad casting?

[Keith.P]

I don't think you are able to fit a seal any more, I would fix the end float as that seems to be what the problem was and see if its usable, thicken up the oil if need be.
To be honest I have never had one apart, Its a little modern for me.

[Nudge]

Sometimes it is not replaced after a gearbox clean out and the gearbox will not mesh properly.

That is what the problem is with one of mine.
when I opened up the gearbox the gull shat on the floor!



I also broke a bolt trying to get apart... No problem! Just added some heat and wound it out with some side cutters.


I think I will make a bronze thrust washer to fix this one.

Thanks for the drawing Keith.

[Merry]

I don't think you are able to fit a seal any more, I would fix the end float as that seems to be what the problem was and see if its usable, thicken up the oil if need be.
To be honest I have never had one apart, Its a little modern for me.

Why don't you think I could use a seal now?
Also I don't know what you mean by fixing the end float, I've had a good search on here, is it the movement in the shaft?

[Collector Inspector]

"End float" is not the exact terminology as the shaft in operation does not "Float in operation" but here goes......

The washer is a shim that defines the together meshing between the gears (Pinion and Crown Wheel) when the propeller is pushing them apart via the prop shaft under load.

These "Shims" are available from John and three different thicknesses are available in a wee kit.

There may be wildly differing unloaded "Float" of the shaft between any individual motor but that is not the concern as above.

The meshing clearance is the deal. There is no actual adjustment for minimum meshing clearances as who would want to limit an opposed free play when NOT under load Aye?

B

[Keith.P]

The seal seat or where the seal mounts has worn away. You can no longer fit a seal.

End float means the movement or play in the shaft horizontally.

This picture shows the parts better.

[Charles uk]

Please note there are 2 thrust washers, one on the prop shaft & one above the pinion gear, these hardened thrust washers are available in 3 different thicknesses & are still available from John or British Seagull for about £1 each, same washers in both locations.

The washer on the prop shaft is subject to the full "push" from the prop, which tends to wear it thinner, causing a side loading on the pinion gear & increased wear in the pinion shaft bearing, as your Seagull cannot be less than 20 years old & possibily as much as 75 years old & no one knows how much abuse it has suffered in it's life, it might pay if your planning on working it hard, to giving this area a little TLC!

It will certainly extend it's life expectancy!

Thanks for the illustrations Keith, they paint an easy to understand picture.

[Merry]

Did I read that a century gear box with a prop from a forty plus be an upgrade?

[headdownarseup]

Sorry guys with the missinterpretation of "thickness" washer or thrust washer. Same thing. (i thought i already covered that in my last post)

End float (sometimes known as "backlash") is the engagement between gears. Too loose (i.e no thrust washer) will give you lots of play in/out on the prop shaft. Too tight will give you very stiff to turn gears.
Just re-read my original post, and i mentioned there are sometimes (not all the time) 2 thrust washers that sit on the same prop shaft immediately behind the main gear itself. (viewed from the end cap side as in your pics) 1 thick one and 1 really thin one. Sometimes all it takes is that really small washer to be missing and this will give you bad backlash (end float) As you have neither of them, this is where all the play is coming from. (does that make any sense!)
Fit a new thrust washer (not a bronze one) and refit the end cap to see if anything has improved.
Chances are that the gears themselves will be quite worn anyway. (have a butchers at the teeth to see if they're pointy!)
If your gears are worn then your gearbox will ALWAYS be noisey.

The saltwater corrosion has really gotten into this gearbox hasn't it!
The front view shows this where the prop shaft comes out of the box where the prop sits.
There was (or should be, what's left of it) a "ring" for want of a better word cast into the casing to house the rubber washer. This has clearly rotten away. There is nothing stopping you replacing this rubber washer with another new one. Once the brass collar is back in place this should hold most of it in place. Every little bit will help to retain it's oil.
By the looks, the only other option is to look for another box.

I might have another gearbox casing that perhaps will be a bit better than what you have if you get stuck. (i've got over 60 old and dirty gearboxes than i know what to do with waiting to get stripped for spare parts, but these featherweight boxes are quite hard to come by)
Let me know if you think you're going to need it after all this....


Jon

[Merry]

Ok, well I'm now starting to build a picture in my head of how it should all be. I do have the thrust washers, but they came off before the brass collar did, I'm guessing they should be between the brass and rubber?
Is the rubber seal washer just a grommet? Is it specific in anyway at all? I'm now thinking about grinding off what's left of the worn "seat" and maybe remaking it.
Unless I can come across another gearbox. What are my options with other gearboxes?

[Charles uk]

The location of the thrust washers is well illustrated in both pictures, they are both inside the gearbox.

Most gearboxes have either never been fitted with the rubber "grommet" or lost it, so it not being there will make little difference.

[Merry]

Ok cheers for everything guys.

Jon where abouts are you located incase I need another box?

[headdownarseup]

Just had a quick butchers through my boxes of bits. (i've got loads of gearbox bits and bobs so don't be scared to ask)
Sorry, no spare gearbox i'm afraid.

I'm in Bristol by the way. (but i can travel)



Rebuild what you have with the correct parts. I'm sure it will be good enough for what you want.

I think there is still some confusion as to the placement of various "washers" (thrust or otherwise).

I will put up some pics a bit later to help you with certain questions if you need it.

Jon

[Merry]

Yes that would be very helpful and much appreciated thank you.
Glenn