what's with clutch / shifting problems???

You say it has in/out (axial) play. That kind of indicates the clutch is loose on the mainshaft or the mainshaft is moving which it shouldn't since it's pulled up tight to the right side bearing with a large nut. Any extra freeplay will use up the limited pushrod travel which is only about 0.12". Check the clutch centre nut first.

mwoo - what do you mean by the "clutch release bearing" There is no such part description in the parts book for a Mark 3.

do you mean the clutch sprocket bearing ( # 06-0750?)

Yes, the clutch center nut is tight.

Had it off last week to dig down to the bottom of this problem, and reassembled it with locktite and good torque. (But will go double check it after dinner - although this tough clutch has been with me for a long time, well before taking off the clutch center nut last week).

Yes there is play in the mainshaft (or at least i can detect play on the clutch basket around the mainshaft)

Hi Keith - yes I did mean the clutch centre bearing (060750) - it's also worth checking that the circlip (060752) to ensure that its holding the bearing correctly.

The clutch centre bearing also needs to be "deep grove ball bearing - one dot".

I once replaced a clutch centre bearing with an ordinary type, and the basket would rock on the bearing, but was informed by the learned members here on the forum that it needs to be the above type. I think the "one dot" indicates that the tracks are deeper, and this eliminates nearly all of the "rocking" motion that you will get on the clutch basket with a standard type bearing.

the clutch center nut is tight and the clutch center is nice and snug with a tiny bit of play in and out with the main shaft.

However the clutch basket is rocking around a lot - with the plates removed. It was rocking as a whole unit before taking the plates out, and I couldn't tell then what was moving. Now that the plates are out of the way, I can see that the clutch center is snug and the basket is moving around quite a bit.

And I now realize there are some nasty grooves in the clutch center teeth too. Oops. Was sure it was in good shape.

So my tough clutch action is either caused by the grooves preventing the plates from moving freely, or by a bearing problem which is causing the freeplay in the clutch basket.

Or both......

I definitely need to replace the clutch center - the grooves look pretty scary, and I might as well change the bearing while I'm in there.

Reggie - thanks for the tip on the bearing. I'll get the one specifically for the Norton clutch.

Thanks again all. Will post the results after i get and install the parts

Keith

still trying to get this clutch working right

Yesterday i managed to get my hands on a new clutch center so i pulled the old one and swapped in the new one last night.

The old one had some pretty serious grooves in it, so I thought the new one would solve the problem - which felt like the plates just weren't lifting enough. Surely this was being caused by them getting caught in the grooves in the clutch center.

But here i am again with the problem still not solved!!!

When I set the clutch adjusting screw to allow just the right amt of pushrod free play, and leave just a bit of free play at the clutch lever, the pull seems to be softer, but ------- it is not disengaging the plates. If i screw out the adjuster nut at the lever enough to where i can roll the bike forward with the clutch in (in 1st gear), then a full pull of the clutch is still real hard - and it jumps out of neutral into first sometimes, and is real hard to shift sometimes too.

The only things I have not done:

1. added to the clutch stack height. I measured it and it is bang on spec (friction plates are fairly new, and even checking the stack height with the old stock friction plates, the height is OK (at 1.15" from the bottom of the plate stack to the very top of the pressure plate). And I have about 30 thou of space between the edge of the diaphram spring and the locking ring, so I don't see how I could get another plate in there anyway???

2. replaced the bearing behind the clutch center. It seemed to spin nicely when i played with it as i replaced the clutch center last night.

anybody else with ideas ???????

PS - Debby - you were right on questioning the clutch center from grooves. I must have originally looked at it while standing toward the front of the bike, and as the groove marks are only on one side of the splines, I didn't see them till I looked from the other direction. At least that's my story and I'm sticking to it.

Keith

The last things you've done before this fault occured were; fitted new plates and changed the cable?

Your clutch lever pull symtoms sound like you've fitted a bad cable. Check the new clutch cable is nylon lined, if it is check the nylon can be seen at both ends. Try a new one, well at worst you'd have a spare.

Check the plates are perfectly flat. Put one on top of another and hold them up to the light then turn one over and check again, repeat with the rest. Accept no deviation at all.

Have you checked there's no end float on the basket?

Cash

Cash -

thanks for the suggestions. Cable is not the problem. I have 3 perfectly good cables that I have experimented with. Routing is not a problem.

Yesterday I tried my final experiment - i got my hands on a regular steel plate (80 thou thick) and added it to the top of the stack. I had to work to get the locking ring back in its groove, but the end result - voila ! the clutch works the way it is supposed to.

Gears shift perfectly. I can shift back and forth between 1st and neutral when stopped. Yeah!!!

So my plate stack height was just not enough I guess. The clutch has been a bit funky since I bought the bike. I suspect the previous owner had one of the thinner pressure plates installed, which would account for the difference, but that's just a guess, since I checked thickness on everything except the pressure plate when I had it apart (which was at least 4 times in the last few weeks).

I am going to shave the thickness of the additional plate a bit, probably down to 65 thou from the stock 80, just so I know the lock ring is not being forced against its will.

So problem solved - although the pull is still not as soft as it should be - at least the clutch is disengaging properly and I can shift the way it is supposed to.

Thanks everyone for all the suggestions. All ready for a ride with the Southern Calif Norton Owners Assoc tomorrow morning. Will try to video tape it and put the video up on my site. If so, I'll add a posting here. Would be cool to have a vid of a few dozen Nortons cruising around on a Sunday morning.

Keith Kelly

Labor Rates:

$35/ Hour
$45/ Hour if you watch
$85/ Hour if you help

Click to expand...

And one more I added to my shop wall ~

$95 / hour if you want offer advice/ tell me how to do the job! @/ @


My clutch was fine after I made sure the new nylon lined cable was laid in a smooth flowing fashion ~ fixed!