gearbox oil ?

[Charles uk]

What prevents the seal that you've fitted in the recess you've made in the top of the pinion bearing wearing rapidly as the rusty pinion shaft that has now lost it's coating of leaked oil as it rotates inside it & damages the lip seals?

The stainless prop shaft doesn't have the same problems providing it's in good condition.

[hippy]

Fair comment. Although where there is a will there is a way. If it only comes down to this being the only obstacle I'm sure it can be overcome. Leave it with me and will get the grey matter working. As a biker also I discovered that soaking fasteners and ferrous metals in fully synth meant that they never rusted. Not sure in this application but certainly worked on my ducati for over 14 years with no rust and some hard and wet riding. Just a thought......

[hippy]

Failing that just throw a stainless sleeve on the oil seal area of the pinion shaft which is a two minute job and wouldn't detract from the strength of the shaft will so little hp going through it.

[Charles uk]

Not possible as you've got 1/2" round shaft turning into 3/8" square, you can't slide a stainless sleeve over that!

[hippy]

Consulted Mr Pythagoras and you are absolutely right, but in checking the answer is simple to this problem. Will try it on my spare box and let you know.

[Collector Inspector]

Hmm

What about the ID of the pinion shaft bush?

BnC

[hippy]

No idea.

[hippy]

Sorry for the short answer, sure it'd be 1/2 inch but recken could take it out to sleeve the pinion shaft. This way could bring any worn bearings/ shaft back up to tolerance. This in itself coupled with cutting a few oil seal recesses would be a fairly quick job. Seals should last longer with a suitable stainless sleeve. Its do-able I reckon, and fairly cheaply. Depending on seal prices and a little labour it wouldn't be much at all. Got a few other little jobs to attend to and then will try it on mine. Will let you know how it goes.

[Gannet]

Hippy,
Original thoughts on how to seal these old gearboxes are more than welcome. Although Charles has mentioned the 40+ 3.5:1 gearbox, the smaller 40- 10:21 is in probably more dire in its need for sealing. This smaller box contains only contains a maximum of 70ml of oil which can quickly be very diluted by water ingress ( especially with a worn pinion bearing and corroded pinion shaft surface). An easy solution to sealing is required. Sure, fitting a new expensive bearing is a solution, but utilising a pinion shaft with very poor surface finish, doesn't seem to make sense to me.

Perhaps you have an answer to this problem? As I have said all ideas are more than welcome.

Jeremy

[hippy]

Hi Jeremy,

I will be looking into the gearboxes such as featherweight, 40 and century.I have not had much to do with other models. Hoping to keep any fix ideas cheap cos I don't like spending money. Have been banding a couple of ideas around with CharlesUK and hopefully come up with something fairly dependable and cost effective. Not too sure there will be any easy fix without some machining but as I have lathe and miller would be happy help out. As soon as can get it done I will throw a post out.
Meanwhile am off to Tremadog bay for a spot of fishing, boating and a few beers.

Dave