AJS & Matchless Owners Club

The correct screws for securing the chain case to the crankcase are small, hex head screws, part no. 000440, used in conjunction with tab washers, part no. 000165, all available from AMOC Spares. The hex head screws used on your machine look to be bigger than the small correct ones. The thread in the crankcase is easily stripped and I'm wondering (hope I'm wrong) if yours have been tapped out to a larger size.

If the crankshaft spacer behind the sprocket is missing, the chain will cut into the crankcase boss as it did on my M18S, I discovered. The slotted, pan head screws in the photo aren't the correct ones, but they did the job.

I'm going to try and get the sprockets off tomorrow, I can't get at the bolts with them in place. I will take the spring washer off and see what's what.

Cheers guys

markwhitelock wrote:I have subsequently seen that what I thought were two different sprockets (primary chain and dynamo chain) are in fact joined together! :

So that leaves me scratching my head about the bolts used to hold the chain case on and whether there is a spacer....

Hi Mark. For future ref you'll really find it a great help and save a you lot of head scratching if you take time to become familiar with the various manuals for your bike in Christians Archive:

http://archives.jampot.dk/book/

In the Spares List for your bike it clearly shows the drive assembly with a one piece double sprocket and the spacer (010629).
It would also help if you mention the year of the bike, either in your post/question or in your Profile.

Yes, I have the parts book, took me a while to find the right bits!

Any tips for getting the sprocket nut off?!

I saw a tip a few years ago to lock the primary chain using a short length of 1/2" square tubing. You wedge it diagonally between the engine sprocket and the clutch sprocket. I tried it a few days ago and it worked for me. The tube has to be just the right length, so a bit of experimentation needed.
Dave.

markwhitelock wrote:
Any tips for getting the sprocket nut off?!

Steady pressure will just get lost in the shock absorbing spring assembly. I'm afraid (Mick D look away now) I bodge if the clutch and primary chain have been removed by shocking it undone by fitting a spanner or socket (there's not much of the nut available for this) and belting the end of the spanner/socket bar with a hammer. Using a rattle gun would be better.
If the chain is still fitted I jam the drive sprocket to the clutch sprocket with a bar spanning between the teeth of the two sprockets. (Likewise to tighten it and also the nut on the clutch centre).
The manual will say that if the clutch and chain are fitted you just engage top gear and put the rear brake on hard then undo the nut but I've never had much success trying to do that on my own.

I was given a 1/2" square drive pneumatic impact driver. It makes short work of getting crankshaft nuts (amongst others) undone.

The impact driver did its job, came off easily.

The splines are really worn, I imagine the Cush drive movement will take up slack but does this look dangerous/excessive?

The parts are laid out as I took them off, there was no spacer to remove. Is the spacer loose or is it in there somewhere and I'm not seeing it?!

Looking at your second picture, I think you'll find that the spacer is in situ on the crankshaft, up against the main bearing inner race.