Clutch Assembly - wet/dry?

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Just about to re-assemble clutch, running with standard primary chain & will use ATF in the primary - is it best to assemble the plates dry or should I give them a light coat of ATF first? I see a note in the workshop manual about oil contamination of plates, which seems wied for a unit running in oil. c
 

Ron L

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F_Magna,

The oil is for lubing the primary chain, not the clutch. The clutch plates are quite happy to run dry as evidenced by the many belt drive conversions.

When filling the primary, fill to a level that just touches the bottom run of the primary rather than to the "full" level hole.
 
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norbsa48503 said:
Just don't try the ATF if you have a mark three.

Quite right ! The old tensioner really doesn't like it, does it ?

I use left-over fork oil in the Mk111 (15 or 20 weight or a mixture!) on the basis that the anti-foaming properties might help in the tensioner and most thin engine oils these days seem to be at least semi synthetic. I haven't had any clutch problems with it.
 

L.A.B.

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I use ATF in my 850 MkIII and cannot say I have experienced any tensioner problems ?
 

Ron L

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If the check valve seat is in good condition and the slider bores are good I don't know why ATF wouldn't work in an MkIII. I have had it in my cafe racer for 15 years with no problem. The chain stays tight even with a hopped up motor.
 
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It was Dyno Dave who told me this,later seen with mine own eyes on what must have been a well used mark three. Straight 20 wt non-detergent compressor oil fixed it right up. As ron says it's the hydo chain adjuster that would cause the problem.
 
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When I first had my Mk111, I replaced tensioner body and both pads and went over to ATF as was often suggested.

The tensioner lost it's prime within a week and this was observable if it was standing with the cover off. There are no oil seals on the pistons and that migratory red ATF just seemed to find it's way out down the bore.

I went back to light engine oil and clutch plate cleaning at 5000 mile intervals :)

The ATF thing is not something that I've ever read about, just something that I observed and made up my own mind on. Maybe my new tensioner was part of the infamous Liquidator's scrap-bin stock ?
 

L.A.B.

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I agree that ATF drains out of the tensioner fairly quickly, (I observed this to be a matter of minutes if the oil is warm, although I wouldn't have thought a higher viscosity oil would have taken that much longer due to the tiny amount held by the feed trough?) but my own has always re-primed itself in a few seconds after start-up as long as the recommended primary oil quantity is used.
 
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Do you mean that every time you start up, the tensioner has lost it's prime ? Mine doesn't normally but if it has, it makes a horrendous noise that lasts for longer than my mechanical sympathy can stand.

I'm not sure about how much oil gets carried around the top chain run.

I have always filled the Mk111 with a measured 200cc as per the book.

Strange beasts, Commandos, no two are alike :D
 
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Thanks for the help - dry it is & being '71, no tensioner to worry about.... now if anyone has some hints on checking the chain alignment & undertanding why the stepped washer at the back of the clutch appears to seat onto the circlip rather than the shaft shoulder.... :?:
 

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Wear in the tensioner and oil viscosity (and temperature) would obviously affect the rate that the oil drains out, but without actually testing how quickly various grades of oil compare it is difficult to say.

Dyno Dave could have done that?

I checked mine once (one day I when I had the cover off just out of idle curiosity more than anything else!) and the trough emptied itself of warm ATF in about 20 minutes, but as I said previously the tensioner seems to re-prime fairly quickly and work normally after. But I certainly wouldn't rule out using an alternative oil.
 
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F_Magna said:
Thanks for the help - dry it is & being '71, no tensioner to worry about.... now if anyone has some hints on checking the chain alignment & undertanding why the stepped washer at the back of the clutch appears to seat onto the circlip rather than the shaft shoulder.... :?:

The manuals are quite good on alignment using a straight edge along the chain wheels although I find it easiest to do a "dry run" first without the inner chaincase in place.

The clutch locating spacer is meant to locate with the recess "over" the circlip. What is it that is puzzling you ?
 
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Only draw back of the compresser oil here in the states is having to buy a gallon at a time. If you were to use a detergent oil the mist on the roller bearing chain would attack as it sat not running.
 
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The clutch locating spacer is meant to locate with the recess "over" the circlip. What is it that is puzzling you ?

The recess goes over the circlip, but the rear face of the spacer didn't look as though it would be hard against the shoulder behind.
 
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F_Magna said:
with the recess "over" the circlip. The recess goes over the circlip, but the rear face of the spacer didn't look as though it would be hard against the shoulder behind.

I haven't got a spare mainshaft to hand to check (donated all my old ones to a sidecar racer who kept bending them) but the intention is that the circlip locates the clutch. Without the circlip, there is nothing to stop the clutch moving inwards. I don't recall a step or shoulder on the mainshaft. The circlip should just sit in a groove.
 
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Without the circlip, there is nothing to stop the clutch moving inwards

Ah, thanks, that explains it, I thought perhaps it bolted up to what must be the end of sleve gear shaft/sprocked shaft.

Looks a bit like they left that bit of the design till last!
 
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F_Magna said:
Without the circlip, there is nothing to stop the clutch moving inwards

Ah, thanks, that explains it, I thought perhaps it bolted up to what must be the end of sleve gear shaft/sprocked shaft.

Looks a bit like they left that bit of the design till last!

I think that there are quite a lot of candidates for that last honour :)

If the clutch pulled back against the sleeve gear, it would lock it solid on the mainshaft.

A shoulder could do the same job as a circlip but the mainshaft does have to be able to pass through the sleeve gear bushes and a reduction in section to provide a shoulder would introduce a stress concentration that we really don't need, especially with the Commando's long mainshaft and overhang.

Do check the condition of the circlip because they can mill themselves away against the splines if things loosen off a bit and they are difficult to remove without damage. I always keep a spare handy.
 
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