Clutch Adjuster Cap Oil Seep

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spartanman

spartanman

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Howdy - new Mk3 owner and so far things are going splendidly, except.... twice after fairly long rides.....45 minutes.....I have oil on my exhaust from a seep out of what I believe is called the clutch adjuster cap. Is this normal? If not, is there a fix besides attempting to torque down the cap some more, or would that do more harm than good. Any advice is welcome. Thanks
 
spartanman said:
Howdy - new Mk3 owner and so far things are going splendidly, except.... twice after fairly long rides.....45 minutes.....I have oil on my exhaust from a seep out of what I believe is called the clutch adjuster cap. Is this normal? If not, is there a fix besides attempting to torque down the cap some more, or would that do more harm than good. Any advice is welcome. Thanks
Click to expand...

If you remove the cap you will find an o-ring -or at least a place for an o-ring. If the o-ring is in good shape the cap does not need to be very tight. Jim
 
Make sure you don't have too much oil in the case. Remove the small screw in level check plug and make sure that oil is only slowly dripping out of it.
 
Assuming you have the correct gearbox fitted and not an earlier one you could check that the gearbox breather is not blocked. It is, on a Mk3, the small tube on the inner cover siruated behind the outer covers cable entry point. On previous models the breather was a small hole in the inspection cover (as is still shown on the outer gearbox cover drawing in the Mk3 replacement parts catalogue - publication number 00-5756) but clever owners would polish the cover and block the breather hole so the gearbox breathed via any other outlet including down through the main shaft pushrod hole taking any oil it could gather with it which entered the designed to be run dry clutch resulting in clutch slip problems IF an owner actually applied enough torque to it to induce the clutch to slip that is. So someone with a brain still at NVT introduced the small tube which could I suspect easily block..........
Another trick owners would do is over tighten the two inspection cover fixing screws and bow the cover so it did not seal correctly from that point on..... It might be worth checking yours is flat and if not apply a rubber /hide mallet to it .....with it sitting on a flasolid surface that is !! .... I have the feeling the gasket did not change over the decades as the part number shown in the Mk3 spares catalogue is an old AMC type number 04-0057.. It was /is? a thick paper / cardboard gasket.
Of course some owners overfill the gearbox and even use the wrong grade of oil....... Some even do the same in their primary oil bath chain case and wonder why...never mind.....must be hell being unable to read and not understand what section K8 in the manual states......unless of course they can read but fall into the trap of believing section K9 which used to be section K8 until the new section K8 superceeded it when some clever soul made old section K8 the new section K9 contradicting the new section k8 !!
 
J. M. Leadbeater said:
Assuming you have the correct gearbox fitted and not an earlier one you could check that the gearbox breather is not blocked. It is, on a Mk3, the small tube on the inner cover siruated behind the outer covers cable entry point. On previous models the breather was a small hole in the inspection cover (as is still shown on the outer gearbox cover drawing in the Mk3 replacement parts catalogue - publication number 00-5756) but clever owners would polish the cover and block the breather hole so the gearbox breathed via any other outlet including down through the main shaft pushrod hole taking any oil it could gather with it which entered the designed to be run dry clutch resulting in clutch slip problems IF an owner actually applied enough torque to it to induce the clutch to slip that is. So someone with a brain still at NVT introduced the small tube which could I suspect easily block..........
Another trick owners would do is over tighten the two inspection cover fixing screws and bow the cover so it did not seal correctly from that point on..... It might be worth checking yours is flat and if not apply a rubber /hide mallet to it .....with it sitting on a flasolid surface that is !! .... I have the feeling the gasket did not change over the decades as the part number shown in the Mk3 spares catalogue is an old AMC type number 04-0057.. It was /is? a thick paper / cardboard gasket.
Of course some owners overfill the gearbox and even use the wrong grade of oil....... Some even do the same in their primary oil bath chain case and wonder why...never mind.....must be hell being unable to read and not understand what section K8 in the manual states......unless of course they can read but fall into the trap of believing section K9 which used to be section K8 until the new section K8 superceeded it when some clever soul made old section K8 the new section K9 contradicting the new section k8 !!
Click to expand...

As clear, and succinct, and relevant as ever....
 
J. M. Leadbeater said:
Assuming you have the correct gearbox fitted and not an earlier one you could check that the gearbox breather is not blocked.........etc.
Click to expand...

The "clutch adjuster cap" is the one in the primary case covering the pushrod adjuster.
Because of the clutch cable entry, it's virtually impossible for pressure to build up inside gearbox regardless of whether the so-called gearbox 'breathers' have become blocked.

A new cap O-ring will likely cure the problem.
 
On my 1974 Commando both of the large inspection caps on the primary cover leaked oil. Replacing the O-rings just gave marginal results. I believe that my primary cover was machined incorrectly so that the O-rings could not be compressed enough to seal. What I ended up doing is modifying the inspection caps by machining a step in the cap so that the cap could screw down farther and compress the O-ring better. The machined step I made is about .030 inches high with it's diameter of 1.845 inches. When I chucked the inspection cap in my lathe the cap was not perfectly centered however it's not that critical.

After making this modification of the inspection caps I can now feel the O-ring being compressed as I tighten the caps and it solved my oil leak problem completely.

This modification is rather easy to do if you have access to a lathe or even any hobby shop or jeweler's lathe.

Here is a picture of one of my modified caps in the lathe:
Clutch Adjuster Cap Oil Seep


Here is the picture of the modified cap with an arrow pointing to the machined step:
Clutch Adjuster Cap Oil Seep


Peter Joe
 
Alternatively you might try seeking out a metric O ring that fits and is thicker than the imperial one.
That's how I cured a seep from my kickstarter. The original ring wasn't tight enough in the groove. A 25mm x 4mm one did the trick.
 
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