Hitchcocks Forum

On checking the primary chain case oil the previous owner has a very thin red oil in there.Dont want to top up with conventional oil.What type of oil is this red.

Hi, its likely to be transmission oil to make the clutch easier to operate

As Tom said, this sounds like ATF (automatic transmission fluid,) which is generally found to be a Good Thing in the primary drive. When changing or topping-up, use Type F specification (not Dexron.)

What's wrong with dexron AA?
Our hosts recommend it.

Our Hosts actually say they think any ATF works but some of us have found better results with the type F. I've tried both in several Albion clutches (Bullet 3 and 4 plate, scissors on a Connie and splined type on an Interceptor) and I have to say the F does work better overall.

REgards, Mark

Guys completely unaware of this ATF recommended oil I have drained the red oil and filled with a 5w/30 synthetic as quoted in my 2003 service manual.Havn't had the bike for a ride out yet but am I looking at a slipping clutch or what.

It will be fine, but may well feel 'heavier' than with the ATF, possibly leading to poorer gearchanges. Try it and see, some folk don't seem to notice the difference but I do on all my Enfields.

REgards, Mark

Our hosts actually say "And experienced excellent results" when they are talking about DEXRON ATF and go on to say in bold letters "Hitchcocks use MP ATF in their Bullet primary chaincases". So yes they must think it "works"! Some of us get great results from listening to people with more experience than ourselves.

Here is the difference.
Type F had no friction modifers.
Dexron (and Mercon and old type A) has friction modifers.

Friction modifiers change the shift "firmness" and are specified depending upon the clutch and band friction materials used in the manufacture of the transmission. The original GM Hydramatic had metal plates and used motor oil. Some people use the same oil in everything that takes oil in their bikes. In the late 1940's they switched to a fibre friction material and invented a fluid with the correct frictional properties, Type A. The various Dexron formulas are backward compatible to 1949!

If you use Dexron/Mercon in a trans designed for Type A, it WILL slip. Ask me how I know. If you use Type F in a transmission designed for Dexron/Mercon the shifts will be harsh. B&M "Trick Shift" fluid is just relabeled Type F.
In the day Type F was the best fluid on the market. When I worked in a tranny shop in Leeds, we used Type F in everything. Today Dexron III is the best. I would go with Dexron III.Dexron III replaced Dexron II. Unless you have a bronze clutch.

Oh dear