Hole in the primary chain case

pictures (or stories) of hideous injuries sustained by your ariel
roger.fellows
Holder of a Silver Anorak
Holder of a Silver Anorak
Posts: 833
Joined: Tue Feb 21, 2012 8:32 pm
Location: S.Cumbria UK
Contact:

Re: Hole in the primary chain case

Post by roger.fellows »

This may just be an impression, but Ray's spring looks more nearly coil-bound than yours Dave, and the difference between where the nuts lie and the end of the shaft is not all accounted for by the absent tab washer.

Perhaps a few other photos from different angles would give the right clue to somebody who is familiar with all the bits.
User avatar
paul.wirdnam
Holder of a Silver Anorak
Holder of a Silver Anorak
Posts: 641
Joined: Fri Apr 08, 2011 7:50 am
Location: Okeford Fitzpaine, Dorset, UK
Contact:

Re: Hole in the primary chain case

Post by paul.wirdnam »

I didn't explain myself very clearly in my last post...sorry. :oops:

But I'm sure this is just a case of the 3 parts (2 x nuts and 1 x washer) being assembled in the wrong order. If you put a nut on first, then washer and finally last nut, everything will go further onto the crankshaft thread. I do not have the spring retaining cup to be 100% sure but if you look at these two photos, you will see that it is the washer that is preventing full use of the thread. In addition, if the washer is between the nuts, I assume you are mean to bent the many tabs in both directions to lock both nuts:

Image

Image
Paul
User avatar
keith.mettam
Holder of a Waxed Cotton Anorak
Holder of a Waxed Cotton Anorak
Posts: 515
Joined: Wed Mar 02, 2011 1:46 pm
Location: Kent UK
Contact:

Re: Hole in the primary chain case

Post by keith.mettam »

As Paul has correctly pointed out the parts are assembled as he states, i.e after the spring cup is the first nut then the tab washer and finally the second nut then the tabs on the washer are bent in both directions to lock both nuts. With the parts properly assembled the outside nut will be fully on the shaft.
Regards,
Keith.
roger.fellows
Holder of a Silver Anorak
Holder of a Silver Anorak
Posts: 833
Joined: Tue Feb 21, 2012 8:32 pm
Location: S.Cumbria UK
Contact:

Re: Hole in the primary chain case

Post by roger.fellows »

now it makes sense! Thanks
User avatar
ray.tolman
Holder of a Waxed Cotton Anorak
Holder of a Waxed Cotton Anorak
Posts: 335
Joined: Sun Feb 27, 2011 4:53 pm
Location: British Columbia, Canada AOMCC Member 1014
Contact:

Re: Hole in the primary chain case

Post by ray.tolman »

Hi Roger and all,
The spring is assembled correctly but appears to have perhaps less free range of movement, not sure why. The inner nut is tightened up snug against the mainshaft butt.
I do not wish to hijack Dave's thread, but, could there be a problem using just the Blue Loctite and no tab washer?
I do not want to damage the outer primary.
Thanks,
Ray
roger.fellows
Holder of a Silver Anorak
Holder of a Silver Anorak
Posts: 833
Joined: Tue Feb 21, 2012 8:32 pm
Location: S.Cumbria UK
Contact:

Re: Hole in the primary chain case

Post by roger.fellows »

Hi Ray, Dave's is incorrectly assembled. The tab washer is preventing the inner nut from forcing the spring cup to butt up to the mainshaft splines. Nut, washer, nut assembly allows more spring compression. Dave's looks as though it might even allow the cams to ride over each-other.

The photo of Dave's before dismantling shows wrong assembly too. Perhaps this contributed to the failure.
Dave.Barkshire
Holder of a Silver Anorak
Holder of a Silver Anorak
Posts: 866
Joined: Thu Feb 24, 2011 3:33 pm
Location: Exmoor UK & Lamma Island HK
Contact:

Re: Hole in the primary chain case

Post by Dave.Barkshire »

Thanks very much for everyone's observations. Yes I do need to move that washer to the correct position and whilst I'm at it I'll grind the high points off the alloy weld just to make sure. I also have a primary chain case gasket to fit which will give a few thou of extra clearance. Then victory surely will be mine.
roger.fellows
Holder of a Silver Anorak
Holder of a Silver Anorak
Posts: 833
Joined: Tue Feb 21, 2012 8:32 pm
Location: S.Cumbria UK
Contact:

Re: Hole in the primary chain case

Post by roger.fellows »

Just an extra. There are those who recommend a continuous primary chain if it is possible to arrange - to avoid the possibility of fishplate failure. I think Nev Hunter warns against the use of half-links.
User avatar
ray.tolman
Holder of a Waxed Cotton Anorak
Holder of a Waxed Cotton Anorak
Posts: 335
Joined: Sun Feb 27, 2011 4:53 pm
Location: British Columbia, Canada AOMCC Member 1014
Contact:

Re: Hole in the primary chain case

Post by ray.tolman »

Hi Roger, Dave and all,
I am using the 23 tooth primary sprocket so needed to obtain a chain having a cranked link.
I sourced a high quality IWIS chain from Andy, "The Chain Man".
Once again, I hope all is well and the cranked link will not be a problem.
Ray
Last edited by ray.tolman on Sun Sep 17, 2017 9:00 pm, edited 2 times in total.
david.anderson
Holder of a Golden Anorak
Holder of a Golden Anorak
Posts: 1528
Joined: Mon Mar 28, 2011 4:52 am
Location: south coast NSW Australia
Contact:

Re: Hole in the primary chain case

Post by david.anderson »

Dave
That is a very nice repair. It is good to see such work rather than to discard it and source another from a finite resource.
The Iwis Chain and the half link for the Iwis is far superior to some of the other half links that are available. The Iwis chain is superior to the original English Reynolds and is worth the money.
David
Post Reply

Who is online

Users browsing this forum: No registered users and 2 guests