AJS & Matchless Owners Club

Decided to investigate further the rumble I am experiencing on my '48 G80 and stripped the primary drive today. Prior to taking the clutch apart there was a pretty spectacular amount of movement of the whole assembly on the mainshaft - the clutch centre nut was very tight. Removal of the clutch centre showed the state of the splines in all of their glory!

I'm quite prepared to investigate further into the engine if needs be, but has anyone any experience of this kind of wear and it causing rumbling? It certainly looks pretty knackered to me and, I suppose, could well be the source, even though it is more supported when the whole clutch basket is assembled. I think I have located a replacement and will also change the 24 rollers.

Thanks

Iron Head

New Alloy replacements come up on eBay £40-£50.
I had wear on my '54 model 18 clutch splines but not as bad as yours. I also found the clutch rollers were the wrong ones making it jump and snatch. Mine was supposed to have the slightly longer rollers.
Good luck.


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Thanks guys - love the buff right out suggestion!

Hi Iron Head, seen similar wear on a 500cc B52 clutch centre, but never that bad! I replaced mine with a much better autojumble find. I subsequently repaired it by boring out the centre, cutting the centre out of a (lower) 350 version and turning it to fit the hole, then brazing the two parts together - result a 500 clutch centre with good splines. They all wear to some extent and a bit of play is ok if you tighten up the nut good and tight, but yours looks like it could strip the spline remnants, leaving you going nowhere. Andy

Very enterprising bit of engineering there Andy with your clutch centre, well done. It would appear that my clutch centre is effectively G3L. The 5 stud centres seem to be easy to find. You are quite correct in commenting that it is a failure about to happen so I have to find a replacement. Although the nut on mine was very tight it seemed that although someone was trying to take up the wear/wobble previously they may have mainly been bearing down on the end face of the mainshaft rather than applying all of the pressure to the clutch centre. I am also missing a spring washer under the nut it appears.

Iron Head

There is no spring washer under the nut on a Burman clutch only the offset figure 8 locking washer which goes over one stud and the mainshaft then the nut. Maybe your set up isn't correct hence the dramatic wear.

I discovered that my M18 had the shorter 350 clutch centre fitted so I bought a new longer one. Put it all together and found that the last friction plate would disengage from the clutch drum when the clutch was operated. Took it all apart again and found that the the rear 'lip' on the new centre was thicker than it should have been. I put it up in the lathe and turned it back to the same thickness as the original 350 hub. Worked fine after that.

Thanks for the feedback guys the figure 8 tab washer idea sounds good ajscomboman have seen them on the web and think I'll buy one.

Hi Iron Head, just noticed the bit about replacing the rollers in your original post. Check the length in the parts book. Again, my experience is with B52 clutch (which will fit on CP mainshaft, I believe) but the PO on my G80 had fitted 'ordinary' .250 rollers, which are too long and lock up when the mainshaft nut is tightened up. Luckily I found this out before damage was caused, special short rollers are needed, available from Jampot spares. Andy