The BSA A7-A10 Forum
Technical (Descriptive Topic Titles - Stay on Topic) => Gearbox, Clutch, Primary => Topic started by: Minto on 27.05. 2020 21:26
-
On rebuilding my clutch, one of my plates is a bit of a mystery, it's plain on one side but has some kind of friction material on the other, it's also in really poor condition so I'll probably leave it out. Do I have to shorten the push rod accordingly? If so how do I reharden the end?
Cheers
Jase
-
Minto. On the Plunger Clutch the first plate into the basket is a slightly thicker plain plate, 67 3240. The small difference in thickness compared to the other plain plates (67 3241, there are 5) is such that it often ends up in the middle of the pack, by mistake. Its function is to support the spring load on the other plates, so a thinner plate at the back here is detrimental to the proper working and set up of the clutch.
Over time the original may have been lost and substituted by the mystery plate. In the short term use this as the first plate, friction side down, smooth side up, or try adding another plain plate if it seems too flimsy alone. Don't mess with the push rod, get the right parts, the correct number of plates and it will work fine, its a good clutch.
Raising the edge of the clutch centre tab washer can be started with a Mole Wrench, then the tab finally flattened against the nut with a drift if necessary. A soft washer and a strong wrist may be enough.
Before assembly, make sure the small split collar and clutch thrust washer are in place on the gearbox mainshaft. Expect a fair amount of rock in the complete clutch, they all do that as the supporting rollers are somewhat narrow and offer relatively little support to the chainwheel, compared to later designs.
Swarfy.
-
Thanks Swarfy
Managed to pull the edge over with the molies, like you said.
When I was stripping the motor I was surprised at the amount of "rock" in the assembly while it was still all done up. It feels quite a bit less wobbly now. Everything's scrubbed up and back together now apart from getting it adjusted.
I'll replace all the clutch plates when I can afford to, as they're an odd set, with different thickness plates, but the clutch was ok before so should be ok for a while yet.
Cheers
Jase
-
Minto. A bit of well deserved success at last. Use Loctite on the clutch spring adjusters, and try your best to adjust the individual spring tensions so that the pressure plate lifts nice and level. The springs usually have some variation in individual strengths, so may look bit odd height wise when adjusted, but the important thing is that the the clutch lifts evenly.
Swarfy.
Additional. Reading your first post again, I assumed the rogue plate was a plain one (tabs to centre), not a one side worn friction plate.
-
Looking at it this morning it appears to be a friction plate with one side skimmed (badly) to remove the friction material.
Success? I'm not counting any chickens just yet, there's a way to go and plenty to go wrong.
Stand by for more dumb-ass novice questions.
Cheers
Jase
-
here you are minto, chisels for removing cows teeth *lol*
-
Looks like these cows go to the same dentist as me.
Eeek!!
Jase