1955 A10 Spotted at Holme Moss

[Pete Gray]

Out for a long run yesterday in glorious warm sunshine when I spotted this nice A10 parked at the top of Yorkshire's famous Holme Moss, I'm not too good on model identification, is it a Road Rocket ?
I had a chat with the owner, a Lancashire lad in his late 60's who when I mentioned this place of ours said he knows nowt about t'internet and wouldn't know a virtual Forum if he fell over one.
He did however know his way round the machine and when I mentioned leak issues when running my A7 primary in ATF he was most disparaging. He, and his equally knowledgeable mate, told me that the best plan was engine oil, they reckon ATF is too thin and containes some additive which can cause clutch slip ?

[LJ.]

Nice post & pictures Pete, thanks for that! (A good picture for the fella enquiring about silencers and QD spindles too.)

I'm inclined to agree with those lads about ATF, but if it works for you and many others here then that's fine, but I'd *hate* the job of trying to keep it in the cases as I see your struggling with.  I use 20/50 at the correct level.

[Pete Gray]

He was suggesting cleaning the ATF out using petrol - do you think it's OK just to drain and re-fill with 20/50

[iansoady]

ATF doesn't have friction modifiers - if you think about it, automatic gearboxes depend on internal clutches so it would be no use in them. It is however thin and seems to find every opportunity to make a break for freedom.

I used it in the primary of my Norton Commando that I had for 20 years as the sintered clutch plates in those tend to stick and it was fine. But the Commando primary cases are better designed than the A10.

[LJ.]

He was suggesting cleaning the ATF out using petrol - do you think it's OK just to drain and re-fill with 20/50

You need to drain it??

...yeah I'd have thought that to drain and fill with 20/50 would be okay, I don't remember suffering any problems when I did that.

I reckon that because the primary chain case is prone to notorious oil leaks people might be tempted to put extra in to make up for later loss/escape. This could then lead to the problem of clutch slipping if too much oil finds its way between the plates.  wink2

[trevinoz]

I must have an unusual A10. I have ATF in the chaincase and it doesn't leak a drop. Not even from the clutch sleeve!

  Trev.