Primary Chain adjusting bolt

Not open for further replies.
Apr 14, 2008
Country flag
I have just noticed on my 1973 Commando that there is no bolt on the gearbox for adjusting the primary chain. Can anyone tell me what size and type this bolt is so that I can get a replacement?
The adjuster assembly is composed of an eyebolt yoke threaded through a trunnion headed bolt that bolts through the tranny cradle frame.

The large eyebolt slips over the main pivoting bolt with special shouldered head and notched-relief shouldered nut.

Which of all of these parts do you need?

You should be able to order the bolt and any other adjuster parts you need from any Norton parts supplier? Or they can be ordered directly from Andover Norton (ANIL): ... 07&Part=33

The dimensions of the bolt according to the Stainless Fasteners list is: 9/16" x 5" UNF (18 tpi).
Thanks GrandPaul and L.A.B. I will order the correct item.
I didn't realise that it was a special piece. I thought that it would have just been a standard type bolt and nut type adjuster.
As you can see in the image, this is all that is there.
Primary Chain adjusting bolt

While I am at it, if you don't mind. Here is a picture of the bike as we received it, rusty and dirty after sitting behind a shed for 10 years.
Primary Chain adjusting bolt

And as it is now.

Primary Chain adjusting bolt

Still a long way to go but it is a reliable runner now.
Veefore said:
I thought that it would have just been a standard type bolt and nut type adjuster.

In that case, please disregard the bolt information I gave you, as I thought it was the upper mounting bolt that you needed ("no bolt on the gearbox")?
The link that LAB posted will illustrate the parts I mentioned. It appears from the photo that you need to replace that ordinary bolt with the proper one, and it also appears that your trunnion bolt is in place although rusty. You need the eyebolt and (2) nuts for sure, and possibly the shouldered nut for the main upper bolt unless it is affixed to that ordinary bolt (not likely).
Not open for further replies.