Clutch Adjustment Battle

[Jonez69]

1973 850 Commando newbie asking for help... I rebuilt my gear box this spring and now getting consistent clutch operation is becoming a challenge. I follow the instructions in the workshop manual and everything works as smooth as silk. Easy shifts between gears, easy to find neutral at a stop light etc, but then suddenly all the smooth action disappears and shifting gets sticky and finding neutral becomes difficult. I make roadside cable adjustments to get home and when I open up the gear box inspection cover, everything appears normal. I checked the clutch main shaft fixing nut for proper torque just to double check my work. I'm fairly certain that everything is properly assembled.
I'm certain the clutch operating lever body is properly assembled with no parts missing. I think where I am missing the mark is in the clutch rod adjustment. The WSM says to slacken the cable completely at the handlebar control and then check the clutch operating lever for "slight movement to and fro". Does this mean in relation to the cable or in relation to the rod and ball? My suspicion is it is in relation to the clutch rod and this is where I am making my mistake. Any advice, tips, or clarification is appreciated!

 

[marshg246]

1973 850 Commando newbie asking for help... I rebuilt my gear box this spring and now getting consistent clutch operation is becoming a challenge. I follow the instructions in the workshop manual and everything works as smooth as silk. Easy shifts between gears, easy to find neutral at a stop light etc, but then suddenly all the smooth action disappears and shifting gets sticky and finding neutral becomes difficult. I make roadside cable adjustments to get home and when I open up the gear box inspection cover, everything appears normal. I checked the clutch main shaft fixing nut for proper torque just to double check my work. I'm fairly certain that everything is properly assembled.
I'm certain the clutch operating lever body is properly assembled with no parts missing. I think where I am missing the mark is in the clutch rod adjustment. The WSM says to slacken the cable completely at the handlebar control and then check the clutch operating lever for "slight movement to and fro". Does this mean in relation to the cable or in relation to the rod and ball? My suspicion is it is in relation to the clutch rod and this is where I am making my mistake. Any advice, tips, or clarification is appreciated!

You loosen the cable. Then undo the clutch adjustment locknut (drive side of bike). Then turn the adjustment screw in until you feel the slack gone. Then the book says to unscrew 1 turn and tighten the lock nut. I like 1/2 turn.

You'll probably need to loosen and tighten the adjustment screw a few times to get the feel for it. Do not unscrew it much because the actuator on the timing side can move out of place if you do.

Once the clutch rod adjustment is correct, then take all but a little slack out of the cable.

 

[Jonez69]

Thanks, Greg!
I did just as you said, just now. It has to be the correct answer.
BTW, I sent you a personal email yesterday concerning a parts purchase.
Thanks again!

 

[o0norton0o]

Inspect the splines in your clutch hub and clutch basket. In some cases the clutch plates wear notches into the splines so when you squeeze the clutch lever to release the spring diaphragm pressure, the plates don't easily separate because they are caught in the notches... That's a notorious occurrence that causes weird clutch behavior...

 

[marshg246]

Thanks, Greg!
I did just as you said, just now. It has to be the correct answer.
BTW, I sent you a personal email yesterday concerning a parts purchase.
Thanks again!

Yes, and I replied yesterday.

 

[Jonez69]

Inspect the splines in your clutch hub and clutch basket. In some cases the clutch plates wear notches into the splines so when you squeeze the clutch lever to release the spring diaphragm pressure, the plates don't easily separate because they are caught in the notches... That's a notorious occurrence that causes weird clutch behavior...

Everything seemed to be in good condition when I had it apart, but if any problems persist, I will certainly look into this as a possibility. Thanks!

 

[Tornado]

Everything seemed to be in good condition when I had it apart, but if any problems persist, I will certainly look into this as a possibility. Thanks!

FYI, CNW sells a case hardened clutch hub to help solve the notching problem.

 

[Skoti]

1973 850 Commando newbie asking for help... I rebuilt my gear box this spring and now getting consistent clutch operation is becoming a challenge. I follow the instructions in the workshop manual and everything works as smooth as silk. Easy shifts between gears, easy to find neutral at a stop light etc, but then suddenly all the smooth action disappears and shifting gets sticky and finding neutral becomes difficult. I make roadside cable adjustments to get home and when I open up the gear box inspection cover, everything appears normal. I checked the clutch main shaft fixing nut for proper torque just to double check my work. I'm fairly certain that everything is properly assembled.
I'm certain the clutch operating lever body is properly assembled with no parts missing. I think where I am missing the mark is in the clutch rod adjustment. The WSM says to slacken the cable completely at the handlebar control and then check the clutch operating lever for "slight movement to and fro". Does this mean in relation to the cable or in relation to the rod and ball? My suspicion is it is in relation to the clutch rod and this is where I am making my mistake. Any advice, tips, or clarification is appreciated!

Could it simply be an overtightened primary chain or belt drive?

Because everything normally works ok when the motor is cold, but once heated up gear shifting can get sticky and neutral becomes difficult.


Good luck

Skoti

 

[Jonez69]

Could it simply be an overtightened primary chain or belt drive?

Because everything normally works ok when the motor is cold, but once heated up gear shifting can get sticky and neutral becomes difficult.


Good luck

Skoti

Definitely worth looking into if problems persist. I have about 3/8th inch play cold. It all seems to be in the clutch set up/adjustment at this point.

 

[YING]

Jonez,
Let us know how it works out.
Mike

 

[Jonez69]

Jonez,
Let us know how it works out.
Mike

Will do. Poor weather in central Iowa yesterday, so no long rides, just a short test up and down the block. Planning a 50 mile ride today with sunshine,
I'll know within 20 miles if the problem is cured or not.

 

[NPeteN]

"Run the clutch cable down till theres plenty of slack on it. Adjust your clutch rod until it touches on the center screw (clutch side). Back off about a quarter turn on a commando, lock the nut up and make sure there is a bit of free play" (on the cable operating lever, inside the gearbox).

Works everytime.

 

[Jonez69]

View attachment 119458
"Run the clutch cable down till theres plenty of slack on it. Adjust your clutch rod until it touches on the center screw (clutch side). Back off about a quarter turn on a commando, lock the nut up and make sure there is a bit of free play" (on the cable operating lever, inside the gearbox).

Works everytime.

NPeteN, Thank you! I think I am getting the hang of making the adjustment. As I said in the opening post, it's the "to and fro" wording that left me unsure.
Are they referring to the up and down movement of the lever as the cable would move it or in and out movement toward the inner gear box. I believe now it is referring to the latter. With the ball bearing and clutch operating lever in their proper place, the rod is snugged up to the ball with the adjuster on the clutch side, then backed off. You have to admit, it is an interesting design, to say the least! If I can cover 50 miles of suburban and country riding without
the problem recurring, I think I will have it solved!

 

[Richard Tool]

I had a problem finding neutral after total redo of my Commando and slacking the primary chain a tad solved it - been a few years now and no recurrence.

 

[kerinorton]

I follow the instructions in the workshop manual and everything works as smooth as silk. Easy shifts between gears, easy to find neutral at a stop light etc, but then suddenly all the smooth action disappears and shifting gets sticky and finding neutral becomes difficult.

That comment prove sits not the clutch hub splines the plates engage with. If it was, you are likely to have had the problem from the start. I had some problems years ago, and eventually I found the nuts on the end of the main shaft had come loose.
Firstly I found the clutch hub nut had come loose, solved most of that by fitting a decent thick washer against the hub before putting the nut back on, also making sure the lock tab stayed engaged. That made things better, but later Ii had a similar problem, which was caused by the r.h. mainshaft nut coming loose. No lock tab to secure that so loctite was the answer.

There are quite a few things about the Commando design which were not very well thought out. One is the clearance allowed between the splines on the mainshaft and the ones inside the clutch hub, allowing rotational movement, which ends up causing the clutch washers holding the hub between the circlip and the main nut to wear, hence coming loose.
As for the chain being too tight. You have to make sure when you adjust the primary chain that you wind the adjuster forward, to prevent the pull of the rear chain moving the gearbox backwards.

 

[ashman]

Primary chain and rear chain adjustments can throw things out if not done right and cause problems with clutch problems, all 3 play a part to get things right, also cable run, both chains need to have the right amount of slack with no tight spots in the run, it can be a bit tricky getting it right.

 

[Jonez69]

Jonez,
Let us know how it works out.
Mike

Well, my test ride reached a fail point at about 10 miles. Smooth as silk up to when it wasn't. It became hard to find neutral approaching stop signs. I pulled into a driveway and turned for home defeated.
Here is what is new on the bike-
Complete Andover rebuild kit
New Venhill clutch cable
here's what I have revisited-
Clutch to main shaft nut re-torqued to 70 ft lbs, now using two tabs of the 3 on the tab washer. I did this 2 days ago after finding it loose and thought this was my problem, however, the symptoms persist. Previously I had torqued it to 40 pounds as per Ashley the AN engineer in one of his videos. It was only saved by the single tab on the tab washer.
Main shaft nut on timing side- torqued to 50 ft lbs just moments ago- it was already tight. Previously I had torqued it to 45, so added the 5 ft lbs.
Clutch operating lever body/lock ring was also found loose 2 days ago. I tightened it and it was as it should be today when I disassembled for main shaft nut re-torque.
Next step-
Add a bit of slack to the primary chain and adjust the drive chain
Pray
I guess the only thing I should add is that when it fails the test rides, you know it has failed because you suddenly have a1/2 inch of cable slack that wasn't there when you made the shop adjustments. First 2 or 3 stop lights, going thriough the gears, finding neutral , smooth as glass, no clicks or clunks and then Wham! Slack, and dragging clutch. No amount of handle bar adjustment fixes it. Limp home, take it apart and the clutch operating lever and ball bearing look to be where they should be. I had the lever in its proper place when I made the adjustments before riding. I know I am doing something wrong, but I can't figure it out for the life of me....

 

[NPeteN]

Bring some tools with you. When it happens, pull over and open things up.

 

[ashman]

What clutch plates are you using, stack height right, pressure plate lost its grip maybe, the big C clip sitting fully in its grove for the pressure plate, clutch plates in the right position.

 

[marshg246]

Well, my test ride reached a fail point at about 10 miles. Smooth as silk up to when it wasn't. It became hard to find neutral approaching stop signs. I pulled into a driveway and turned for home defeated.
Here is what is new on the bike-
Complete Andover rebuild kit
New Venhill clutch cable
here's what I have revisited-
Clutch to main shaft nut re-torqued to 70 ft lbs, now using two tabs of the 3 on the tab washer. I did this 2 days ago after finding it loose and thought this was my problem, however, the symptoms persist. Previously I had torqued it to 40 pounds as per Ashley the AN engineer in one of his videos. It was only saved by the single tab on the tab washer.
Main shaft nut on timing side- torqued to 50 ft lbs just moments ago- it was already tight. Previously I had torqued it to 45, so added the 5 ft lbs.
Clutch operating lever body/lock ring was also found loose 2 days ago. I tightened it and it was as it should be today when I disassembled for main shaft nut re-torque.
Next step-
Add a bit of slack to the primary chain and adjust the drive chain
Pray
I guess the only thing I should add is that when it fails the test rides, you know it has failed because you suddenly have a1/2 inch of cable slack that wasn't there when you made the shop adjustments. First 2 or 3 stop lights, going thriough the gears, finding neutral , smooth as glass, no clicks or clunks and then Wham! Slack, and dragging clutch. No amount of handle bar adjustment fixes it. Limp home, take it apart and the clutch operating lever and ball bearing look to be where they should be. I had the lever in its proper place when I made the adjustments before riding. I know I am doing something wrong, but I can't figure it out for the life of me....

Assuming no bad parts, you still aren't getting the clutch pushrod adjusted right or the cable is not properly in the actuator. Unlike some other British bikes, the actuator can slip out of place if the adjustment is too loose. Look in the inspection hole of the gearbox. The cable end should be in the actuator and clearly visible. With the cable slacken at the handlebar, the actuator should have only slight up and down movement. If it does, loosen the clutch adjuster screw about a turn and see if the actuator stays in place but has a little more movement. There really is no way for the symptoms you have to exist if the parts are good and the actuator is in place.

The clutch actuator may well be misaligned if that lock ring was loose but that should only cause hard clutch pulling, not your symptom. If it were very loose, then the rod and actualtor would not in their proper places.

We need a picture in the gearbox inspection hole, and in the outer chaincase inspection hole where you adjust the clutch rod.

Also, many here hate the tab washer becuase the nut can come loose. That only happens if you're missing the steel washer that goes between the tab washer and nut - number 58:

Read here for my (and others) thoughts on tightening the nut (57) under the Primary Case heading - you're now WAY too tight: https://gregmarsh.com/MC/Norton/Info/NortonTorque.aspx