Billet clutch basket surprise...

Stu Bodycote

Stu Bodycote

VIP MEMBER
Joined
Jun 12, 2020
Messages
1,363
Country flag
Just stripping down a mk1 Sport with a transmission concern....gotta say...this clutch basket sub-assembly is a new one on me!
 

Attachments

  • Billet clutch basket surprise...
    20211121_182410.jpg
    227.4 KB · Views: 321
Stu Bodycote said:
Can you see the problem?
Click to expand...
Is it the rivets not peened or are you showing us the way the cush spring is captured ? With less end of spring support ? This is an early billet clutch ? The starter ring gear looks a bit chewed up also . BUT the spring is at the center of your photo , So it is the spring support you are pointing out ?
 
Stu Bodycote said:
I'll do a quick video later guys
Click to expand...
The spring pocket in the back plate is too wide and isn't touching the spring. The clutch will 'stroke out' before it reaches the spring, therefor not damping the basket movent. Also, the rivets don't look annealed and havn't peened over or swelled enough because they are too hard. Hence they are standing proud of the rear back plate.
 
Yeah, kinda realised the picture actually shows you lot sod all. It was a long day yesterday, so excuse me.
Nikoli is pretty much spot on though. The basket its self is almost fully floating. I'll pull it apart later, see what the basket is like where the springs locate...there's a lot of movement going on though
 
Nikoli said:
The spring pocket in the back plate is too wide and isn't touching the spring. The clutch will 'stroke out' before it reaches the spring, therefor not damping the basket movent. Also, the rivets don't look annealed and havn't peened over or swelled enough because they are too hard. Hence they are standing proud of the rear back plate.
Click to expand...
So that’ll rattle like a bag of spanners then!

Wonder how common this is and if it’s a cause of the horrid noises some bikes emit (like mine did, gotta be honest, it was a big factor in selling it).
 
Maybe I'm missing something here, but it looks ok to me. The spring acts between the spring pockets in the clutch basket and the spring slots in the plate holding the ring gear. The backing plate holds the springs in place, but they don't act against it.

Ken
 
I think what we are looking at is normal for the early clutch and it's that same as mine (with hand engraved part numbers) The silver plate (which I've highlighted green here) we can see beneath is fixed to the drive gear and the black plate is just the retainer for the springs which has a small gap around its circumference (the red line). The springs are partially sunk into machined pockets in the basket, which is what gives the damping. It probably would have been a lot better to have the retainer and the basket in contact with the spring I guess?, but that would likely cause even more rivet failures. :rolleyes:

1637603895738.png


The pockets in the aluminium clutch basket could be wallowed out as seen recently on FB, but I think that was due to failed rivets...


1637604364730.png
 
Last edited:
That is really nasty looking. For comparison, this is what mine looked like after the rivets gave way. It shows a little of the same sort of wear, but I was fortunate to find it before it got as bad as yours, so I was able to re-use it.

Billet clutch basket surprise...


Ken
 
Yeah, crap post on my part...nothing to see here by the picture. The video wouldnt upload...Im guessing I need to use youtube or something?
There was an horrendous amount of movement on this. Stripped it down to find similar wear as shown by cliffa. Thing is, the rivets weren't loose...very sound and secure. I wrongly assumed, hands up, that this had been incorrectly assembled and was probably missing the spacer and conical washer. But no, both were present. What I did find though was compression limiters that Ive never seen before (I didnt have much to do with the older billet clutches whilst at Norton....if there was a problem with one, we just fitted a later unit), and the one's I have pulled apart before still had the same compression limiters as found on the later stuff. Anyone else seen these before?
Also need replacement basket, and starter ring gear, as thats got quite a few chipped teeth as well as the usual wear.
Norton are still saying no on spares as I emailed them this afternoon regards replacement rivets. Annoying given that they show pictures of completed 961s at Solihull.
 

Attachments

  • Billet clutch basket surprise...
    20211122_174736.jpg
    257 KB · Views: 218
Thankfully that's not my clutch Ken, but I was pleased to see that mine has buttons inserted into the springs which will spread the load. My bike came through the Swiss importer Fritz Egli and I believe they used to strip and re-assemble the bikes, so perhaps it was done by them.
 
Last edited:
Stu Bodycote said:
Yeah, crap post on my part...nothing to see here by the picture. The video wouldnt upload...Im guessing I need to use youtube or something?
There was an horrendous amount of movement on this. Stripped it down to find similar wear as shown by cliffa. Thing is, the rivets weren't loose...very sound and secure. I wrongly assumed, hands up, that this had been incorrectly assembled and was probably missing the spacer and conical washer. But no, both were present. What I did find though was compression limiters that Ive never seen before (I didnt have much to do with the older billet clutches whilst at Norton....if there was a problem with one, we just fitted a later unit), and the one's I have pulled apart before still had the same compression limiters as found on the later stuff. Anyone else seen these before?
Also need replacement basket, and starter ring gear, as thats got quite a few chipped teeth as well as the usual wear.
Norton are still saying no on spares as I emailed them this afternoon regards replacement rivets. Annoying given that they show pictures of completed 961s at Solihull.
Click to expand...
Hi Stu, never tried posting a video on here, so cannot advise.

Nasty wear in there eh? any idea how far it was moving? I have mine out at the moment, but as the rivets have already been tig welded I'm loath to open it up. I can feel about 2 or maybe 3 mm play.

By "compression limiters" are you referring to that the oval shaped spacer which the rivet is passing through in your picture?

Hopefully Ollie can help with the bits.
 
For comparison here are some pics of mine on another thread...

961 gearbox

When you get bearing out, take it to a good bearing supplier, given the number he can replace exact size with a heavy duty bearing, usually having a extra ball or two
www.accessnorton.com www.accessnorton.com
 
Stu Bodycote said:
Has anyone found a local supplier for replacement rivets?
Click to expand...
We have used ARP bolts on some and we have had some substitutes "rivets" made then while having a press hold everything we weld the "rivets" we made in place. Both methods are fine and better than original.
 
You must log in or register to reply here.
Back
Top