Gearbox oil

[grollinson]

On checking for the first time the oil level in the gearbox of the 1949 Flying Squirrel I bought earlier this year (I haven’t done many miles) I find that it appears to contain Silkolene Super Two (i.e. the oil is red). Four litres of Super Two was supplied by the previous owner and I’m using it in the tank, but the gearbox doesn’t seem an appropriate place for it. I’d appreciate some opinion though before I drain the box and put Morris 50 grade in there.

[Barrie]

I use 85w140

[BRIAN MARSHALL]

Hi, when deciding on oils please note that there are entirely different SAE viscosity grades between engine oils and gear oils. I usually put a 140 grade gear oil in Scott gearboxes, which is roughly equivalent to a 90 grade engine oil. Don’t bother with gear oils that have EP before the viscosity rating. This stands for Extreme Pressure, and the additives smell vile !
Brian 🙂

[Ted Robinson]

Do not use EP OIL IN THE GEARBOX it destroys the phosphor bronze bushes. Ted.

[Tman]

Is this advice still relevant? I thought the formulation was changed decades back and now EP is OK to use with phos-bronze bushes..?

[PaulR]

I have used THIXOTROPIC grease which turns to oil on activation for many years now,

Origionally Tich Allen recommended this.

Available from Hitchcocks, the Enfield people and used in Enfields of course. Regards.

[chris wastell]

Me too. Never had any trouble with it, corrosion etc… 🙂

[gammakeith]

I would caution against thixotropic grease as my gearbox had this added when I got the bike. When I stripped the box I found it was in a right state with badly rusted bearings (close to collapse) and some associated pitting on the gear teeth. The box appeared to have been well rebuilt with new a output shaft bearing but had done very few miles since. I accept, protracted storage may well have been a confounding factor though………

Keith

[BRIAN MARSHALL]

I know that the Morgan Three-Wheeler owners used to advocate thixotropic grease (Shell Tivela Compound A), but then went off it after several recorded cases of the stuff emulsifying to an off-white corrosive sludge. To my way of thinking, for an emulsion to form there MUST be water present, and perhaps Morgan transmissions let water in ? I can’t see how a Scott three-speed gearbox can get water in it, even from condensation, so Keith’s experience is puzzling….
Brian

[Martin Heckscher]

I switched to Silkolene’s thixotropic grease well over 15 years ago because the Sprint’s gearbox was leaky. It largely prevented the leaks, and when I stripped the box following the crash at Dijon in 2009 everything was in virtually perfect condition. I also use it in my other Scott 3 speed gearboxes.
Martin

[gammakeith]

@BRIAN MARSHALL wrote:

I know that the Morgan Three-Wheeler owners used to advocate thixotropic grease (Shell Tivela Compound A), but then went off it after several recorded cases of the stuff emulsifying to an off-white corrosive sludge. To my way of thinking, for an emulsion to form there MUST be water present, and perhaps Morgan transmissions let water in ? I can’t see how a Scott three-speed gearbox can get water in it, even from condensation, so Keith’s experience is puzzling….
Brian

I agree it is puzzling. There was no evidence of any water/emulsification and the thixotropic grease appeared fine. I cannot believe the guy went to all the trouble of getting the output shaft sleeved/rebushed without at least checking the bearings in the box. Those bearings were very dry as well as rusty so I concluded at the time that the grease just was not getting into the bearings properly? I guess it is also possible that it was a different grade of thixotropic grease or even possibly just simple Moly grease?

Keith

[Graham Parker]

Morris lubricants do a “Semi-fluid” grease which I think is thixotropic. It is branded K400EP with 3 different grades available.

Morris’s pride themselves on providing quails, specialist oils and are active as a family in vintage activities in the Shropshire border area.

Whilst it is an EP and markets for use in modern commercial vehicle central lube systems ito is also clearly stated as being suitable for vintage / veteran vehicle applications – so assume modern EP properties avoid copper/phosphor bronze earing adertivespecially

[Graham Parker]

In case anyone is interested …..

I’ve just rebuilt my Gearbox and will use Morris Oils AG140 (non-EP). If this does manage to leak out I’ll move to their semi-fluid grease “K4000EP”.

I just spoke to their technical department and they actually have Scott 3-Speed Gearbox listed in their database with both these options as being suitable.

Cheers

Graham

https://www.morrislubricants.co.uk/

[Tman]

I filled my ’47 with 140 on recommissioning and it leaves an annoying drip wherever it goes. Over the winter it’ll be drained and “Spheerol” semi-fluid grease added.
This stuff keeps my Enfield relatively clean, and if it can do that to an Enfield… 😉

[Colin Butler]

I have used Morris semi-fluid in all three of my Scott’s for several years
All internals look great, including the race bike.
Ran at 102.6 mph at Montlhery,I stripped the box when I got back, all good.

[Author]

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