Hitchcocks Forum

Posted: **Sun Nov 15, 2015 9:20 pm**

Hi everyone can someone help me as i am new to enfields.I have a electa x and have changed the engine and gearbox oil.I want to change the clutch oil.What oil should go in it ?,I have some EP 90 left from the gearbox would it be ok to use that ? thanks for any help !

Posted: **Sun Nov 15, 2015 9:28 pm**

Dexron III (ATF oil) or something with a similar viscosity is more than adequate to lubricate things without causing too much clutch drag.
EP90 is definitely too viscous

Posted: **Sun Nov 15, 2015 10:42 pm**

I wish someone could explain the benefits of ATF oil. I only eliminated clutch drag by returning to the recommended 15/40 engine oil. The only benefit I found with ATF was being able to find the source of a leak by the colour of it.

Posted: **Sun Nov 15, 2015 11:03 pm**

Hi Gavin and Frank: Automatic Transmission Fluid is very thin but able to tolerate very high temperatures, think of Taxis in gridlock traffic, cars towing caravans in mid-summer on car-park type motorways. It is ideal for Royal Enfield clutch plates. For an interesting read.

http://www.snowvalley.20m.com/bikes/clutches.htm

Posted: **Mon Nov 16, 2015 7:35 am**

I use 20/50 engine oil.

Posted: **Mon Nov 16, 2015 10:46 am**

All at 100C: atf has similar viscosity to 20 engine oil and 90 gear oil has similar viscosity to 50 engine oil (google tells me), I just use 15/40 engine oil because it's what I've got, also primary chain probably never gets near 100c. Worked for me for last 20K miles without problem....

Posted: **Mon Nov 16, 2015 5:53 pm**

Frank et al - slush boxes operate by using a series of 'overdrive clutches' and the friction material is stuck on with a water soluble glue (something a bit better than wallpaper paste I suspect), just like the multiple wet plate clutch on the RE. Which is why any water is a clutch killer. A solvent based glue would come unstuck straight away in oil. So ATF is a really good oil to use on them.

Semi-useless information - ATF is the only red oil allowable for automotive use, any other red fluid means recycled or agricultural; sub-standard. Not all ATF are red.

Posted: **Mon Nov 16, 2015 5:55 pm**

Another thought - I doubt EP90 is JASO MA1 i.e. for use on wet plate clutches.

Posted: **Mon Nov 16, 2015 6:00 pm**

The number after a motor oil gives the SAE number (Merikan Society of Automotive Engineers) which is a viscosity. Problem is there are a number of different viscosity measurement systems and a seperate series for crankcase vs gear oils. This table should I hope add to the confusion - http://media.noria.com/sites/archive_im ... able_2.gif

Posted: **Tue Nov 17, 2015 3:20 pm**

Leon, that was a thoroughly good article. Informative and entertaining.