Topic: CB 400FOUR Clutch rattle

[jgr1946]

My 400 four clutch rattles rather, better now I have the idle set up correctly, but its still there. There is almost no spring left in the clutch basket, or housing, anti backlash gears. Mileage of 56k in traffic has something to do with this.
 Now, how do I get in there to fix it, as its a riveted assembly and no breakdown is shown in the parts list? I have seen some reference to changing clutch shock rubbers but there was no info on how to do this.  I can drill and tap for bolts but am very reluctant to attack without info as I don't have a spare.
Many thanks,
JohnR - in Cold Old England.

[Bodi]

Spring? Not sure what you mean. There are no anti-backlash gears, just plain gears. There are rubber cushion blocks, but they're in the primary chain driven sprocket and probably not accessible without splitting the cases (might come out the bottom, I've never tried that).

[Brian G]

better now I have the idle set up correctly,

I'm assuming you're referring to the idle mixture - that's an important part, to be sure, but have you synchronized the carbs recently? I was contemplating digging in to the clutch on my wife's 550K because of the rattle but when I checked the carb sync, they were way out. After setting them up with a Carbtune, the clutch rattle has almost completely disappeared!

Good luck,
Brian

[ttr400]

Yes you are correct in that there are 6 cushion dampers in the gear on the clutch basket, this is not a part that is available as the whole assembly is riveted together.

You can see if these are worn by the play in the gear to the basket. At first (before I had one apart) I thought the play was in the rivets. When excessive play is found it is due to the cushion dampers shrinking and allowing back and forth movement. This will cause more backlash than you would want, I don't know if it will cause a rattle though.

Solution:
Remove the gear from the clutch basket. You will immediately see why it has play.
Install new cushion dampers and rivet together.
OK, you can not buy new dampers you are saying.......coming soon a new overhaul kit including 6 new dampers and new rivets. this kit is under development and will be on the market in the near future.

Kevin

[333]

A quick way to tell if it is carb sync is to have the bike idling in neutral and pull in the clutch.  If the rattle stops, sync the carbs, and ride off into the sunset.  If it doesn't stop, sit down for a clutch rebuild.

[jgr1946]

Yes you are correct in that there are 6 cushion dampers in the gear on the clutch basket, this is not a part that is available as the whole assembly is riveted together.

You can see if these are worn by the play in the gear to the basket. At first (before I had one apart) I thought the play was in the rivets. When excessive play is found it is due to the cushion dampers shrinking and allowing back and forth movement. This will cause more backlash than you would want, I don't know if it will cause a rattle though.

Solution:
Remove the gear from the clutch basket. You will immediately see why it has play.
Install new cushion dampers and rivet together.
OK, you can not buy new dampers you are saying.......coming soon a new overhaul kit including 6 new dampers and new rivets. this kit is under development and will be on the market in the near future.

Kevin

Excellent, that sounds just what I want. I guess I will see it on your website when available?

[ttr400]

Yes, keep checking the website. It won't be long as I am busy with some motor builds right now that need them.

Kevin

[jgr1946]

There are rubber cushion blocks, but they're in the primary chain driven sprocket and probably not accessible without splitting the cases (might come out the bottom, I've never tried that).

Err yes, I hope its not them as it's a motor strip down to fix. I am just going on what people say and the fact that the clutch outer (basket) gears have lots of free movement.

[jgr1946]

better now I have the idle set up correctly,

I'm assuming you're referring to the idle mixture - that's an important part, to be sure, but have you synchronized the carbs recently?  After setting them up with a Carbtune, the clutch rattle has almost completely disappeared!

Good luck,
Brian

Err, no. Next job I think.