Clutch ballbearing

[G3L1946]

Good morning,

I am just in the process of removing the clutch ( 1955 G3LS ) and on removal of the clutch spring pressure plate ( G-38-2 ) a ball bearing dropped out. The only place I can see that this could have come from is between the thrust rod and the thrust cup. Is this correct? Hopefully I have referred to the parts correctly! Nothing else has been removed as yet, I await a big spanner!
Thanks ,

Stephen

[Rob Harknett]

http://archives.jampot.dk/technical/Tra ... rawing.pdf
The small ball bearing should be on the other end of the thrust rod.

[clive]

Hi again Stephen. See here for an exploded diagram of your gearbox. http://archives.jampot.dk/technical/Tra ... d_view.pdf
The ball bearing should be at the other end of the clutch push rod. Sometimes if the pushrod is very worn am additional ball bearing will be used to take up the slack. You can try to find out if there is a ball the other end by pulling out the pushrod, adding a spot of grease to the end and reinserting it. When you again pull it out the ball may come with it. If it does not, it does not prove it is not there as it may just be better adhered to the operating mechanism.


Ah Rob quicker than me

[Samuel]

You can try to find out if there is a ball the other end by pulling out the pushrod, adding a spot of grease to the end and reinserting it. When you again pull it out the ball may come with it. If it does not, it does not prove it is not there as it may just be better adhered to the operating mechanism.

Les at Russell Motors told me this one. He also gave me a large blob of very stiff grease which did the job.
I think I still have the blob wrapped in a small piece of paper somewhere

[Rob Harknett]

No telling what may had gone on Clive. Perhaps the PO never put a ball in, then discovered the adjuster could not be screwed in enough, then discovered the error and found it easier to put the ball the clutch end. If the thrust rod was so worn, you would have thought that would have been replaced. If a ball is also found the other end, then the thrust rod is too short. So that should be replaced with the correct length thrust rod ( 37-3-4 from club spares for 1955 G3/LS Burman B52 gearbox ) + ball the gearbox end.
Note. The bike may have been fitted with a 55 comp gearbox which has a longer thrust rod. Sizes of rods are stated in the parts list and club spares.

[clive]

It also occurred to me that the the clutch may be 5 plate and have a four plate push rod. The difference in length is 5/16 the size of the ball. 4 plate clutch is 9 7/8 and 5 plate clutch 10 3/16. The pushrods are supposed to have a hardened end but they often wear into a cup shape where the ball sits, effectively shortening them. The available adjustment is usually enough to cope with this but if you add an extra pair of plates, or even a set of new friction plates it can be too much. Stephen you do want to check if possible you have a ball at the correct end.
If you have the wrong pushrod the club sells them.

[ajscomboman]

I've seen this so many times on a Burman clutch, the adjuster is hollow and those not familiar with the correct set up often assume that a ball bearing should be in the hollow of the adjuster when actually it is the opposite. The rod should slide into the hollow adjuster and assist with lifting the plate square. There should be a 5/16 ball but it goes in first before the rod and it runs against the thrust plunger in the lifting mechanism at the filler end. The plunger is the part that really wears but people don't usually go that far as the cover has to come off and simply cheat and put a ball in the hollow.

[Rob Harknett]

You can try to find out if there is a ball the other end by pulling out the pushrod, adding a spot of grease to the end and reinserting it. When you again pull it out the ball may come with it. If it does not, it does not prove it is not there as it may just be better adhered to the operating mechanism.

Les at Russell Motors told me this one. He also gave me a large blob of very stiff grease which did the job.
I think I still have the blob wrapped in a small piece of paper somewhere

Don't worry if you ever need that grease to fish out a ball bearing and cannot find it Samuel. Use one of those little telescopic probes with a magnet on the end. I have used one for many jobs fishing out small metallic bits. I recall a load of steering head bearings drop and roll under bikes out of reach. The little telescopic magnet enabled me to reach the bearings to save moving out bikes.

[Pharisee]

I've seen this so many times on a Burman clutch, the adjuster is hollow and those not familiar with the correct set up often assume that a ball bearing should be in the hollow of the adjuster when actually it is the opposite. The rod should slide into the hollow adjuster and assist with lifting the plate square. There should be a 5/16 ball but it goes in first before the rod and it runs against the thrust plunger in the lifting mechanism at the filler end. The plunger is the part that really wears but people don't usually go that far as the cover has to come off and simply cheat and put a ball in the hollow.

That's exactly what I found had happened on my M18S. The steel ball was in the pressure plate adjuster and the pushrod had almost worn through the operating mechanism. To compensate for the wear, the PO had put a second steel ball back where it should have been in the first place.

[Rob Harknett]

I've seen this so many times on a Burman clutch, the adjuster is hollow and those not familiar with the correct set up often assume that a ball bearing should be in the hollow of the adjuster when actually it is the opposite. The rod should slide into the hollow adjuster and assist with lifting the plate square. There should be a 5/16 ball but it goes in first before the rod and it runs against the thrust plunger in the lifting mechanism at the filler end. The plunger is the part that really wears but people don't usually go that far as the cover has to come off and simply cheat and put a ball in the hollow.

I had mentioned to the effect a PO may have cheated Rob. I cannot recall what bike, but I once found 2 trust rods one short the other long with a ball in between the two.