EP oils best for Norton gearboxes

I've used ep oil in my gearbox for the last decade or more with no noticeable problems. There is slight leak form the kickshaft bearing and 3rd gear is a little noisey but both problems existed before using ep and they haven't become any worse. Ep oil is also what I use on the final drive chains of both my Norton and old VFR. After a ride I apply it with a paintbrush to the inside of the lower run, leave a rag beneath to catch any drops and then wipe of any excess before the next outing.

Mick

When i ran out of chain spray lube i tried EP, what a mess!! Won't try that again.Would you believe i still have a tin of Linklife!!, Too much trouble.

My 99 gearbox has notched up over 220,000 miles on EP oils. Its only failure was a layshaft bearing - not the oil's fault. One emergency chainlube I use from time to time is self-levelling grease, normally used in my Douglas gearbox. (Did I just mention a non-Norton?) I brush it on with a paintbrush. No significant fling and it stays on for a fair while in the rain. Yes please Skip - I would like to see the full report.

This has always been a contentious issue. Some manufacturers specified engine oils, some transmission oils. There were early concerns that 'active 'Sulphur containing Extreme Pressure wear protection would cause problems with bronze and brass gear box components. The Anti Wear agents used in engine oils are less aggressive to these metals but are less efficient at protecting against seizure under high loads.Specifications require the passing of tests for Cu corrosion and modern Sulphur/ Phosphorus containing transmission oils can be used in our Nortons without risk.

The American Petroleum Institute is responsible for confusion over viscosity grades because it uses a different set of numbers for engine and transmission oils even though they have similar viscosities at 100 deg C.

You can therefore use a 75W90 or a 80W90 gear oil with confidence. I have never used Automatic Transmission Fluid in my gearbox, the low friction additives might improve gear changing. Has anyone tried this?

When fully synthetic oils, for gearboxes, started to appear around twenty years ago, this is what I started to use in all my Norton Twins. It was a bit pricey compared to the standard EPgoo from thelikes ofCastrol but the local oil expert claimed that, for your money, you got far less water absorbsion, greatly extended change intervals and a far superior lubricant under extreme running conditions.

I would say that, inmy exerience, he was correct. I change all my gearbox oils every 5 years (12 to 15,000 miles of bike use) and often what I have drained off looks very similar to what originally went in.

I stripped 2 of my boxes, last year, as part of major rebuilds and found absolutely no wear worth a mention. I was able to re-use all of the bearings and only needed to change thegaskets and seals.