Clutch Slipping when kicking Over

[TaylorP]

I'm having some issues with the clutch slipping on my Super Rocket when I'm kicking it over. I've drained the oil and removed the chain case cover and the problem has disappeared. I'm using Silkolene classic straight 40 and wonder if I should switch to ATF. Has anyone had similar issues?

[Triton Thrasher]

SAE40 is awfully thick for a primary drive.  Is it recommended somewhere?

[TaylorP]

It was recommended on the Facebook BSA site to use engine oil.

[a10 gf]

Should'nt it work fine in "any" oil? Was originally made for same as goes in the engine.
Questions would be plates & springs in good shape \ correctly adjusted tension \ correct freeplay.

ps, an intro post is always appreciated :O)

[berger]

don't oil the plates it's a dry clutch with oil for the chain

[ellis]

Hi TaylorP,

I had similar problems using SAE 40 oil. I changed to SAE 20 and the problem went away. You could also try lowering the oil capacity a little as the oil is mainly there to lubricate the chain and the clutch basket bearing, although it only relies on a bit of fling now and then. Hope this helps.

ELLIS

[Black Sheep]

I use 10w-30 tractor universal oil. It's a diesel oil but also used in hydraulics and oil-immersed brakes - no anti-friction additives. Perfect for primary chaincases and forks for that matter. Added bonus - it's cheap and easily available on-line.
No clutch slipping in the A10 or even the Norton Atlas.

[Colsbeeza]

For Interest.
I have had a slightly different issue with my new 4-spring clutch. On assembly, I installed the 20 rollers using some grease to hold them in place. I had 30 Monograde oil for chain lubrication. The operation was great! but after a few hours the clutch would not disengage, making gear changes into and out of first gear impossible. I think in hindsight, I used lithium grease as that is what I had on hand.
On dismantling, there was black gunk on the steel plates which would only come off with my 8" rotary steel brush attached to my grinder. The gunk was so stubborn, I thought I might have to resort to a file. The clutch came from Draganfly as a special ( interpret as bargain) offer. I cannot see anything wrong with the fibre plates, so assume the lithium grease residue was to blame.
I am refitting it tomorrow, and will lay the clutch centre on its back and install the chainwheel horizontally ( I did that last time OK but with grease) and use a little light Automatic Transmission Fluid DX-111 on the rollers. Then fit the inner basket and place the whole thing on the gear mainshaft. Will use ATF DX-111 for chain lubrication, it is about the same viscosity as SAE 20, which I cannot seem to find here in Australia. If the problem returns, I will toss the fibre plates and get a set of Surflex plates.
Has any member had such a problem?.
Col

[TaylorP]

I suspect the oil level has been too high, I'm not yet sure how, but it could be  that I hadn't let sufficient oil out of the level plug. It could also be wet sumping but I don't think so. The question is now, do I need to strip and clean the plates, given that its working OK without oil. Also do I refill with a different oil ( any recommendations?) Thanks again for the help. I will write an introductory post later today, as usual just came in from the garage with lots of questions.

[berger]

yes clean the plates and do some research on the level plug, people have been known to change them over the years, I had one that was in a bsa case that was 3mm taller than my old one and that's a lot of oil

[ellis]

I would limit the oil capacity in the chain case 190cc max. I never had a clutch problem and this amount of oil was enough to lubricate the chain.

ELLIS

[muskrat]

G'day TaylorP.
I have used bearing grease to hold the rollers without any issues in the past. ATF is my preferred lubricant (easy to spot a leak as it's red). Friction modified oil is a no no.
Wet sumping into the primary is usually only on early (pre 53) plungers and rigids. Your SR will/should have a crankshaft seal.
Cheers

[TaylorP]

OK quick update, contrary to what I found last night the clutch slips without the chain case cover on. So its a slightly different problem. Heres what I've found so far.
- clutch adjustment at the basket, way out, must have been slipping like this for ages.
- clutch friction plates appear to be new, pressure plates nearly new, probably how the previous owner got away with the above.
-Clutch plates have lots of oil on them, this could be me over filling or the previous owner, I will never know.
- after initial tightening down of the clutch springs and seeing a good improvement, I've stripped and cleaned the clutch and I'm in the process of reassembling it and deciding if I go for ATF or a lighter mono grade (best I can find so far is a straight 30) thanks for the help i will keep you posted.

[RDfella]

Many modern cars use oils as low as 10 or even 5. Admittedly multigrade, but should be widely available. I learnt a long time ago that oil and clutch plates don't mix (the ones like ours, not modern bikes).

[Sav]

Had problems with my A10SR clutch slipping with fairly new surflex plates and researched it quite a bit

I use JASO MA oil  (no friction modifiers) in the form of Shell Advance 10-40 which is specifically made for wet motorcycle clutches.

I have not had a problem since.