Draining the mayo out the gearbox

[headdownarseup]

I think by now, most of these gearboxes will show some signs of wear and tear. Some more than others

The basic design of all these gearboxes (not including the later sealed boxes) rely on having a reasonable seal between a phosphor bronze bushing and a hardened steel shaft. The rubber washer i mentioned earlier is just a grit seal not a sealing washer. (it wears too) The component that usually wears the most is the bushes, usually the pinion wears first then the prop shaft bush.

The technical data states tolerances for the pinion as 0.4985"/0.499" and the pinion bearing as 0.500/0.501"
So how much play is acceptable? apparrently not that much before oil leaks out and gets replaced with water.

I might be able to help with a good second hand prop shaft bush or two, but the bigger problem will be the pinion and bush. Its not too bad to remove as long as you have a good blow torch on standby. Finding a replacement on the other hand......


jon

[Merry]

Well if I push the prop and turn it, it can actually miss the cogs and turn freely if that makes sense?
When I had it open the rubber washer looked a bit past it, should they be fairly thick? I'm thinking if it was thicker it would hold the gears better.
Also this is a 89 fort featherweight, would it be a sealed box? Should I not have taken it apart?

[headdownarseup]

There shouldn't be that much play on the prop shaft in/out. This amount of play (backlash) is taken up by a thickness washer ( in some cases one thicker one and one thinner one together) right behind the main gear and in between the end cap bushing. While the prop is submerged and providing thrust, the direction of the shaft moves slightly forward and the full force is resting against that little washer. If this little washer is missing/badly worn, it might explain why the gears disengage while under load!
The rubber grit seal you mentioned is normally a bit thicker than what you have and will help to keep the oil where it needs to be for a bit longer, and also help to firm things up a tad.

Was the motor noisey at all when you last used it on a boat. Did it sound like there was a lot of whining coming through the transom?

I might be able to help with a couple of small bits and bobs that'll help shut things up for a while, prop shaft bush and a thrust washer perhaps.

Just ask if you get stuck with anything
Always happy to help another seaguller


jon

[Merry]

I've never had It on a boat, its new to me.
Well the rubber one seems very thin and worn, if I can get the bush off and the shaft out could I pack it with any old grommets to hold It back?
To remove the bush is there just a pin through it that needs punching out?
Thank you so much for your help so far by the way,

Glenn

[Charles uk]

Nobody's mentioned the thrust washer yet?

Sorry I didn't read what I'd typed, I meant thrust washer.

Read through previous posts on the subject to learn more.

[Merry]

I'm new to This, thrust washer?

[Keith.P]

Ditto Charles.
The thrust washer, a washer between the front bush inside the gearbox nose cone and the crown wheel, basically a spacer.
Sometimes it is not replaced after a gearbox clean out and the gearbox will not mesh properly.

[Collector Inspector]

No Pics!

We Love Pics!

Another gearbox Ebay or one of our members way to go if in what appears to be "Terminal Doubt"

Reading above and no pics..........replace it aye.

Just a Thort.

B

[Merry]

Any specs on it? Or pics or diagram etc?

[Keith.P]

If it helps.

[Merry]

That does actually
Any idea what it's made of?

[Keith.P]

The same as the shaft I would Imagine, see what end float you have to see if that's the problem and add a washer, stainless one maybe.

[Merry]

Hope these pics work

[Merry]

Whoops, same one twice

[Merry]

That is a pin through that bush isn't it? Not a grub screw?