Clutch Friction Plate thickness specs '67 CL77

[Snakeoil]

I did a search on clutch plate thickness and found nothing.

I measured friction plates on my '67 CL77 today and they all measure about 3.85mm. Spec in my CB77 manual says the friction discs should be 4.8-4.9mm and to change them out at 4.4mm. I did the arithmetic and if my 5 friction plates were 4.9mm, they would stick out of the clutch basket by about 1/8".

Is there a typo in the CB77 manual?

Thanks,
Rob

[davomoto]

Those specs are for the early 4 plate clutch. I use mine down to 3.6mm.

Davo

[LOUD MOUSE]

Like davo says that info isn't current today.
I always use the ones with the wide/black contact area and aluminum core. ...........lm

I did a search on clutch plate thickness and found nothing.

I measured friction plates on my '67 CL77 today and they all measure about 3.85mm. Spec in my CB77 manual says the friction discs should be 4.8-4.9mm and to change them out at 4.4mm. I did the arithmetic and if my 5 friction plates were 4.9mm, they would stick out of the clutch basket by about 1/8".

Is there a typo in the CB77 manual?

Thanks,
Rob

[Snakeoil]

My clutch has the metal core discs. I did a search before I posted and found a thread that talked about the various clutch configs that Honda used. I think it was LM that went thru the history, with 2 then 3 then zero and back to two retaining wires as well as fiber versus metal friction plates.

I have a spare and early '65 CL77 engine that came with my bike. The clutch in that bike had the fiber friction discs. But they also measured almost the same as my metal core discs. That clutch uses 3 wires.

I would assume that when the grooves in the friction material are worn away, the discs are shot.

So I would assume that the free length for the clutch springs is also not correct for a later clutch. My springs were marked with white paint, which was also called out in the above mentioned thread. Anyone know what the specs for free length on those springs should be.

LM, were there service bulletins that contained these various changes? If so, are they available anywhere?

regards,
Rob

[LOUD MOUSE]

Did the 3 wire hub have the original first steel plate?
I haven't seen any HONDA bulletins on all the clutch changes.
AS I only use the white springs I'm not to concerned about the free play.
My knowledge comes from working on many engines and noticing the differences. ......lm

My clutch has the metal core discs. I did a search before I posted and found a thread that talked about the various clutch configs that Honda used. I think it was LM that went thru the history, with 2 then 3 then zero and back to two retaining wires as well as fiber versus metal friction plates.

I have a spare and early '65 CL77 engine that came with my bike. The clutch in that bike had the fiber friction discs. But they also measured almost the same as my metal core discs. That clutch uses 3 wires.

I would assume that when the grooves in the friction material are worn away, the discs are shot.

So I would assume that the free length for the clutch springs is also not correct for a later clutch. My springs were marked with white paint, which was also called out in the above mentioned thread. Anyone know what the specs for free length on those springs should be.

LM, were there service bulletins that contained these various changes? If so, are they available anywhere?

regards,
Rob

[Snakeoil]

Well, you made me go outside to the shop and take a look at that old clutch. Here's what I found.

1. First, I misspoke. It does not have 3 wires, it has 3 holes in the hub for 3 wires, but there were no wires in the clutch when I disassembled it.

2. There are 6 fiber type friction plates and 6 steel plates. I did not measure them, but all the steel plates appear to be the same thickness.

3. The spline in the hub is the small diameter spline.

regards,
Rob

[davomoto]

The last 3 clutches I took apart that had the all fibre plates, all had 6 friction discs, and 3 retainer wires. When reloading them with the 3mm first disc, and 5 of the aluminum center friction discs, the wire holes are covered.