AJS & Matchless Owners Club

My M18 got very rattly on a trip out last year. Investigation revealed that the nut had come loose on the inlet rocker shaft and had actually fallen off. I had to dig it out with a telescopic magnet thingy. The rocker arm hadn't come off the splines, fortunately but it was loose and floating about sideways abit. The arm never disengaged from the pushrod, thankfully,

From time to time I have read “you will need very thin spanners to adjust the push rod length”. I can readily see that most of us will need three spanners, but why a thin one?

Pharisee's photo of his open rocker box helps make my point. Observe the image in his posting above. Trying to get a tight grip on the hexagonal cup on top of the push rod is easy. Simply rotate the crankshaft to cause the push rod to rise in the window, and use a common spanner to complete the task. Roll the engine back to TDC to check your work.

Ciao, DC

You will find that most "standard" thickness spanners will not get at the bottom nut without fouling the one above it. I ground down an old spanner so it fitted as I had a spare.

mikeydpippin wrote:I don't want to be the one in the rear view mirrors sat on the side of the road...on the first rideout .

Don't worry; if you've only gone a couple of miles Dudley would probably be there already to chat with, (or arriving soon after in the breakdown van).

Cerberus wrote:You will find that most "standard" thickness spanners will not get at the bottom nut without fouling the one above it. I ground down an old spanner so it fitted as I had a spare.

Adjust the clearance and do the locknut up 'finger' tight. Rotate the engine until the valve is at full lift and there is plenty of room to get normal size spanners in to tighten the locknut. Check at TDC again afterwards.