Vincent twin clutch

[BigEd]

Ok Big Ed, I'm perplexed. From what I can see your jig is for setting the depth of the plungers. What sets the pressure on the plungers?

Phelps.

The instructions supplied by Roy Cross for using the jig are posted below. I thought that I had already posted these but on a quick check I can't see them in this thread. I am getting ready to catch a plane for a short break to see my brother in Spain so my time is a bit limited at the moment. I may have some more clutch shoe information. While I'm away I will try to find any extra information that I may have on my laptop or in "the cloud".

Vincent Clutch Plunger spring setting fixture​

If the intention is to fit new linings, the old linings and rivets should be removed now.

If the existing linings are to be used then a hole to clear half inch diameter needs to be drilled through the lining of each shoe to access the screw C12. Since this hole needs to be in line with the plunger and thus tangential to the lining it is best machined with a slot drill in a milling machine. However, if only hand tools are available it is probably best to drill a pilot hole through the lining which is then opened out with a rotary file.

The adjusting screw C12 and the old springs are removed and a check made to ensure that the plunger is able to move freely. New springs PD27 and OP11 are fitted and the screw C12 replaced.

The clutch shoe is then located on the half inch diameter spigot in the center of the fixture. The directional arrow cast in the side of the shoe should point anti clockwise with the plunger against the three eighth diameter pillar bearing the same part number as the shoe.

The shoe should now be rotated to depress the plunger against the pillar and the screw C12 screwed in or out until the five sixteenth diameter toggle link hole in the end of the shoe is approximately aligned with a similar sized hole in the fixture with the springs fully compressed.

Put a dab of paint on the end of the screw to lock it in position.

If you now have to fit new linings my recommendation is to forget the rivets and send the shoes and the new linings to “Saftek” and get them to bond the linings to the shoes. With a file chamfer the outer ends of the new linings before assembly.

Roy Cross

29.10.2007

 

[BigEd]

Ready to leave so found a few minutes to do some searching and found the information below. I can't remember who wrote it so unfortunately I am not able to credit it to the author. I think it might be one of our very knowlegable London members, possibly Paul Packman. (Perhaps someone will be able to tell me who wrote it so I can give them credit.)


Clutch Plunger Spring Pressure Adjustment.

I was interested to read the letter in the October issue of MPH from Roy Cross regarding the Vincent clutch. I have lived with a Vincent clutch for the past 38 years and suffered various malfunctions which I have overcome (I think!).
I have climbed the long learning curve associated with this complicated piece of equipment and persevered with it and managed to get it working properly, when it becomes a delight to use.
Roy mentions the two centralising plungers and the importance of their correct adjustment.

Both plungers are pushed by their springs against a stop within their housings. I’ve found that it is important that these are adjusted so that the shoes are concentric with the drum.

There should be a clearance ofabout O.025” between all the liners and the inside of the drum. The plungers can be adjusted by putting drill bit down the plunger hole and removing metal from the stop (carefully by hand) or fitting a plunger of the correct length.
The centralising spring pressures are import and this is where Roy’s set up rig would come into play.
I have managed to adjust these over the years by trial and error. Referring to the little picture on page 29 of MPH 765 (magnifying glass at the ready) the centralising plunger on the right hand shoe (C7/1) helps to centralise that shoe but only comes into play when the engine is being kicked over or when throttling back on the overrun. That being so, the spring of this plunger can be reasonably slack and pushed in easily withtwo or three pounds of thumb pressure.
The plunger on the left next to the C7 is the critical one as it holds off the shoes being engaged by the pilot cutch when it turns the plate carrier and ‘straightens’ the two little dumbbells to become more radial to engage the two clutch plates with the drum.
I made a hole in the lining in my left clutch shoe so I could adjust the spring pressure and found that if the spring is too tight it holds off the engagement from the pilot clutch resulting in clutch slip and if the spring is too slack the clutch snatches. When an in between adjustment is found the clutch can beengaged smoothly with no slip and operated with one finger – bliss.
I am glad a more scientific approach is becoming available to preset these springs of the Vincent Clutch instead of having to strip this complex component to adjust spring pressures so many times as I have had to do.


Note.

Removed the smaller of the two springs in the C7/1 shoe plunger to lower pressure required to depress the plunger. This gives approximately 3 lbs pressure need to fully depress it.

C7 plunger is much harder to depress, maybe 20+ pounds to fully depress.

Both plungers set on jig. Eddy – 14-04-13

 

[Bill Thomas]

Another thing I thought was a good tip, From Big Sid, For the springs to work right, The plungers need to be just touching the pins, There was a lot of slack in mine a few years ago. Cheers Bill.

 

[tatty500]

"..... my left clutch shoe so I could adjust the spring pressure and found that if the spring is too tight it holds off the engagement from the pilot clutch resulting in clutch slip and if the spring is too slack the clutch snatches. When an in between adjustment is found the clutch can beengaged smoothly with no slip and operated with one finger – bliss."




I believe that if the adjusters are screwed too far in the shoes may be held away from the drum because the springs can become coil-bound. On my old B the expanded diameter of the shoes was only about 25thou bigger than the drum ID.

So, it probably won't be because of too much spring pressure that slip occurs, more likely the springs are limiting travel.

This is perhaps what the setting using the jig achieves. Sufficient travel with the most pressure.

Maybe as the linings wear this means the adjusters need unscrewing when originally set at this limit. With riveted linings there was less wear possible.

Tatty

 

[Goffy998]

After much time & expense I gave up with the V 3 clutch & had Bob Culver recondition the original clutch, which now behaves almost as a clutch should. It goes into 1st with a bit of a clunk, which is annoying as silent 1st gear selection was the only the only part of its operation that I got right before. I'm sure a bit of fiddling will cure that. Other than that it's perfect. Full marks to Bob.
The mods I made to give more clutch opening with the V 3 clutch made the take off from a standstill very difficult, so I've replaced the clutch lever with 1 1/8" centres with one with 7/8" so at least it's rideable, I may get round to restoring all back to std. at one point.
I understand that having a spare clutch on the shelf will ensure continual correct operation of the one fitted so I will keep it as an ornament. Best use I can think of.

 

[timetraveller]

Did you fit one of my needle roller thrust race mods to the outer plate? If not then you will find that is helps. I do not have any for sale but the Spares Company stocks them.

 

[Goffy998]

I made something similar so that the plate was always pushed out square

 

[Gene Nehring]

Ready to leave so found a few minutes to do some searching and found the information below. I can't remember who wrote it so unfortunately I am not able to credit it to the author. I think it might be one of our very knowlegable London members, possibly Paul Packman. (Perhaps someone will be able to tell me who wrote it so I can give them credit.)


Clutch Plunger Spring Pressure Adjustment.

I was interested to read the letter in the October issue of MPH from Roy Cross regarding the Vincent clutch. I have lived with a Vincent clutch for the past 38 years and suffered various malfunctions which I have overcome (I think!).
I have climbed the long learning curve associated with this complicated piece of equipment and persevered with it and managed to get it working properly, when it becomes a delight to use.
Roy mentions the two centralising plungers and the importance of their correct adjustment.

Both plungers are pushed by their springs against a stop within their housings. I’ve found that it is important that these are adjusted so that the shoes are concentric with the drum.

There should be a clearance ofabout O.025” between all the liners and the inside of the drum. The plungers can be adjusted by putting drill bit down the plunger hole and removing metal from the stop (carefully by hand) or fitting a plunger of the correct length.
The centralising spring pressures are import and this is where Roy’s set up rig would come into play.
I have managed to adjust these over the years by trial and error. Referring to the little picture on page 29 of MPH 765 (magnifying glass at the ready) the centralising plunger on the right hand shoe (C7/1) helps to centralise that shoe but only comes into play when the engine is being kicked over or when throttling back on the overrun. That being so, the spring of this plunger can be reasonably slack and pushed in easily withtwo or three pounds of thumb pressure.
The plunger on the left next to the C7 is the critical one as it holds off the shoes being engaged by the pilot cutch when it turns the plate carrier and ‘straightens’ the two little dumbbells to become more radial to engage the two clutch plates with the drum.
I made a hole in the lining in my left clutch shoe so I could adjust the spring pressure and found that if the spring is too tight it holds off the engagement from the pilot clutch resulting in clutch slip and if the spring is too slack the clutch snatches. When an in between adjustment is found the clutch can beengaged smoothly with no slip and operated with one finger – bliss.
I am glad a more scientific approach is becoming available to preset these springs of the Vincent Clutch instead of having to strip this complex component to adjust spring pressures so many times as I have had to do.


Note.

Removed the smaller of the two springs in the C7/1 shoe plunger to lower pressure required to depress the plunger. This gives approximately 3 lbs pressure need to fully depress it.

C7 plunger is much harder to depress, maybe 20+ pounds to fully depress.

Both plungers set on jig. Eddy – 14-04-13

Thanks Eddy for the jig drawings. I have used the one I had made to set three shoes this weekend. It works a treat!

I will post a photo, it looks exactly like your one posted earlier in the thread.

 

[litnman]

Any comments from anyone running with the inner spring (PD27) removed from the plunger? More scientifically, what should the spring pressure be.
As shoe C7/1 is engaged, the spring tension is reduced. At the same time spring tension on C7 is increased. At 2 or 3000 rpm, how can you balance
the whole pack.

 

[Gene Nehring]