Draining the mayo out the gearbox

[Adrian Dale]

Confusion yes. but Keith's drawing shows positions well, study it. you can clearly see one thrust washer between the gear wheel and the back of the gearbox casing.

1 Thrust washers, Hardened steel, in side the gear box. Add extra washers to adjust end float. Contact John at SOS and buy a pack of washers he will post next day
2 Remove rubber washer to check end play. it may restrict movement and give you a false reading.
3 When end play is corrected replace rubber washer, collar and locating pin.

AJ

[Merry]

Thanks..

So the pinion in the new box seems seized up, well it turns but only with force. However I do feel with the two boxes I now have I will be able to put together one good one, so will hopefully be a happy ending!

[headdownarseup]

Even i'm getting confused now!

Can we clarify which gearbox you are rebuilding?
Featherweight (40 minus) or 40 plus (also fits centuries)
I have plenty of PLUS gearboxes but NO featherweight boxes...
and a tonne of bits for most of them!


Jon

[Merry]

The forty plus gear box is now going to be fitted onto the featherweight, so I'm rebuilding the forty plus box. just been trying to get the split pin out of the pinion shaft to get that shaft out but its a tight squeeze, lol.
Think I've got enough bits atm, but will probably need new thrust washers and some gaskets.

Is liquid gasket an option when it comes to the back of the gearboxes?

[Collector Inspector]

Paper gasket for gearbox cap.

It is the front of the gearbox by the way

I am sort of confused as well..........

B

[headdownarseup]

OK so you're using the 40 minus powerhead (same power as a plus, still 64cc same as featherweight) but you're using the PLUS gearbox. Is that right?

Try and save as many gaskets as you can. Easy enough job to cut out your own homemade gaskets from new gasket paper using the old ones as a pattern.
New ones seem to be pricey for what they are once you include any postage costs. (i'm just a tight git so make-do and mend is one of my watchwords)

As you say, you might have enough bits with what you've already got to make 1 good gearbox from the 2. BTW the bigger prop from the PLUS gearbox will help a little bit in the speed stakes. (but i bet you'd hardly notice any real difference)
I have spares in case you need any

Shhh... dont tell C.I. but i use a good silicone sealant on the end cap to help things seal up a bit better. You might be wise to do the same if the corrosion to the casing on the small gearbox is anything to go by!

We like pics on here.... are there any more of your progress so far

jon

[Charles uk]

Only use RTV on only one side of the 10 thou paper gasket, this saves destroying the gasket every time you remove the end cap.

[Merry]

Well the 40+ looked less chewed up then the one from my featherweight, plus I like the sound of the better gearing!
However the pinion shaft is very stiff in the 40+ box, and I think the shaft may be bent hence why it's so stiff.

Now looking down the shaft from the top, there was a split pin through the shaft, and a washer under that, I managed to remove the pin and washer so now I can move the shaft up and down, but I can't see any way of removing the pinion gear from the shaft itself to get the whole lot out?
Any tips?

P. S you happy I posted pics now?

[headdownarseup]

Before you end up potentially screwing something up. STOP. (it might save you a shed load of work from here on in)

First things first.
The pinion is stiff to turn correct? (partially seized)
Use your blowtorch and apply some heat to the casing in the area of the pinion. (the outside of the casing)
WD40 on standby, squirt some lube down into the bush and with an adjustable spanner on the square section of the pinion start to turn the pinion. Re-attach the square drive tube to help make things a bit easier to turn.
Keep working things back and forth and it will free off. Might take a few minutes but works well enough for what you need.
If you have a power drill that will accept the size of square tube, use it and keep spraying the lube whilst spinning the pinion.
I tend to clamp the drive tube in a vice and turn the gearbox by hand, but whichever way works best for you.
Heat, soak with lube and turn then repeat till free. (make sense?)

The pinion has probably seized from very long periods of inactivity and lack of lube.
If you don't need to remove the complete pinion then leave it well alone. Only tackle this job if you are completely confident you can put it right again.
Trust me when i say it aint easy to remove it in the first place without a good drifting tool and a mahoosive hammer.... (done a few and wished i hadn't)

Clean all the innards and rebuild with the correct parts (same procedure as featherweight box, basically the same design just a bit bigger).

And as uncle Charlie has pointed out, silicone on one side of the gasket when you put it back together.

And yes, we like pics... thanks for that

jon

[Merry]

Ok, I've stopped, I've been using wd40 but not tried heat yet. Will give that a go tomorrow!

[Collector Inspector]

Only use RTV on only one side of the 10 thou paper gasket, this saves destroying the gasket every time you remove the end cap.

Then again only use gasket sealer like non setting Aviation Gasket Sealer on only one side of the 10 thou paper gasket, this saves destroying the gasket every time you remove the end cap.

Not many times that I revisit an Old Dear Refurbishment Gull or otherwise so the gaskets from many makes while stocked, are just in case or for the next one that comes along.

B

[Revolutionary]

Just got a 1966 seagull that hadn't run in 25 years. Thick Mayo!

As I heard the gears ran with a little water mixed in, I tackled the problem by squirting in some fairy liquid and boiling water. Then turned the motor over with a socket attached to a power drill. Rinse and repeat a couple of times until clean water. Then refilled with SAE 140.

As I am new to this, have I committed a cardinal sin? This seemed an awful lot easier than other processes for dealing with mayo.

[Hugz]

Yep, you sure have! Did you lubricate the bore and crank before spinning the motor? The decription I like for gearbox oil is that it should look like Baileys Irish Cream...yum.

Welcome...

[Revolutionary]

I had thrown a spot of oil into the cylinder earlier in my attempts to start. Tried everything to get a spark and then noticed the connector in the ignition lead had slipped back up its sleeve. Put that right and it was off after 25 years long before the first pull was halfway. Quickly stopped and then tackled Mayo.

So gears should not be a prob after my quick wash up?

[headdownarseup]

Top job.
Always nice to get another old dear going again.
Will you give it a spruce up or will it be a regular go-to motor and use as is?

Jon