oil filter

greasemonkey62 · Post by **greasemonkey62** » Tue Feb 15, 2011 4:45 pm

I have had my 1963 model 31 AJS 650cc twin for five months now and wanted to replace the oil and clean out the engine oil filter. I thought it was the highest and most rearward of the two large nuts on the forward end of the nearside crankcase but when I eventually managed to remove the nut all there was is a recess with a couple of (oil? flow) drillings there, nothing else at all, is this right? If this is the oil filter recess (it looks a bit small) I assume there should be a filter of sorts and a retaining spring but as there was nothing there maybe the previous owner left them out for some reason. Anyone who has this model help me out here please?

Ray

1608 · Post by **1608** » Tue Feb 15, 2011 5:01 pm

Please don't be offended, but how have you got by so far without a manual. You have removed the in-let cam shaft bush housing cap. You need to remove the chrome plated hexagon nut situated same side of the engine but just forward of and below the exh cam bush housing.As you undo the nut the filter will be withdrawn at the same time. I would suggest that you wash the filter in petrol, let it dry and then soak it in oil before replacing. This will ensure that the filtre is charged with oil. Good luck
Edited by - 1608 on 15 Feb 2011 5:03:34 PM

petert120r · Post by **petert120r** » Tue Feb 15, 2011 5:08 pm

The filter is behind the lower large nut. It should be felt inside a fine gauze cage. What you have uncovered is the oil distributor which slots on the end of the exhaust camshaft. There is also a second gauze filter that fits inside the feed pipe from the oil tank.

If you haven't done so already. I would suggest investing in a workshop manual, available from Jampot Spares.

1608 · Post by **1608** » Tue Feb 15, 2011 5:08 pm

So sorry, I have re read your post and admit to being a bit too quick off the mark. It appears that you have removed the oil distributor housing nut. There should be an alluminium drum in the void you describe. The filter is located just below and forward of the nut you undid, and its a little smaller. The oil distributor drum is designed to meter oil to the rocker gear. Without it you may suffer over oiling in the top of the engine.
Once again apologies.

MikeM. · Post by **MikeM.** » Tue Feb 15, 2011 5:24 pm

Hi Ray, the oil filter housing nut(cap) is the one that is just below the curved cutaway at the front end of the engine where the dynamo used to be on pre alternator engines. The nut is the smaller of the three chrome nuts the other two being the camshaft tunnels.
The filter is attached to this nut which also contains a pressure release valve, you will need to anneal the copper washer that goes on the nut so that you have a good seal when replacing it. As far as I can remember there is also a valve that dumps oil into the timing chest in the bottom end of the filter tunnel.
Don't forget to clean the primary filter in the oil tank (you have to remove the oil feed pipe from the tank to do this), and the magnetic crankcase filter in the drain plug.
If your crankcase in the housing is one that is separate from the nut I think that it is most possibly the wrong type. I stand to be corected by other members if this is so. The reason for the one piece filter/end cap was because of the introduction of the valve in the end of the tunnel in 1960. Have fun!

greasemonkey62 · Post by **greasemonkey62** » Tue Feb 15, 2011 11:27 pm

thanks all, I have replaced the large nut that covers the completely empty chamber, and have removed the nut which is forward and slightly lower, but, the nut came off as a unit and contains a spring and ball within the nut unit that does not seem to be able to be separated also a long narrow spring came out with this but the filter unit will not come out it seems to be held in by a concave end cap with a hole in it I have tried several ways of getting it out but as yet no joy, the concave end cap is moving but I cannot get it to move past the threaded section does anyone have any tips on this? I have tried screwdrivers of different sizes and the blunt end of drills close to the hole size in the centre of the concave end cap.
Cheers Ray

greasemonkey62 · Post by **greasemonkey62** » Tue Feb 15, 2011 11:39 pm

I do have a service manual but it is vague, I wish there was a Haynes Manual for these bikes, lol. I suspect I need to be a little more vigorous in extraction attempts but didnt want to damage the filter.
Ray.

MikeM. · Post by **MikeM.** » Wed Feb 16, 2011 12:00 am

To remove this alloy end cap you will need an old spoke or a piece of 1/8" dia rod with a right angled bend on the end, cut the end to fit inside the cap then push into one of the holes in the side of cap. With patience the end cap will eventually come out, you can then remove the filter and if you have one of the magnets on a stick take out the cap that should be in the inner end of the filter.
As I said previously I think you should have a one piece filter, check the inside of the filter tunnel and see whether there is a valve in the bottom of the tunnel. If there is you have the wrong filter fitted.

greasemonkey62 · Post by **greasemonkey62** » Wed Feb 16, 2011 12:00 am

thanks for that, when you say one piece filter do you mean it should have all come out with the nut?
also whe you say a valve at the end of the tunnel what does it look like? I am told my bike is a 1963 model, thanks for the info its all very much appreciated.
The bike has been running with no overheating problems by the way.
Cheers Ray

MikeM. · Post by **MikeM.** » Wed Feb 16, 2011 12:00 am

The filter is attached to the nut and will come out when the nut is removed. You will beed either a good torch to see down the tunnel or a long screwdriver to feel the end of the valve where it protrudes into the tunnel. If there is a hole in the bottom of the tunnel someone has removed the valve!
If there is no valve or a hole for it then you can use the filer with its end caps, spring and nut.