Atlas Washer

Hi Jim,  it sounds like you are saying it will fit the crankshaft end, where there should NOT be any washer. Sometimes the removal of the cover pulls the intermediate gear spindle loose and the washer at the back of the gear can drop . Could this be a "replacement " for it that someone has unsucessfully tried to fiddle back in?, Could it be a shim that  had been behind the  ignition  unit sprocket. and fell off un-noticed during  earlier work?. If it indeed was on the crank end ! could it be a crude attempt to hold the cover seal  in position ?. Looking at the engine I do see some evidence of crude  bodges   that  tell a story of  bad work. Also your oil pump seal looks sad.

I think Robert is correct.  This looks like a bad replacement for the 0.10" ground thrust washer that sits behind the Intermediate Gear.

You need..........

THRUST WASHER (D12/939)  or (T2080)

 From Andover Norton it is listed as  part-no: 06.7548

Thanks to Phil  for the  correct technical  information. Fraid I can't find  anything these days. I also only know of these  dastardly bodges as I have been guilty of  most of them myself long ago. I think Jim would be well advised to keep a wary eye  for  the unexpected  as he works his way round the machine.

No washer on the end of the crank where it goes into the timing cover. Also no washer on the end of the intermediate gear shaft where it goes into the timing cover.I can see that  someone could think there could be a use for a washer in these situations ,but  no , the only  big washer used is behind the intermediate gear up against the crank case.   Perhaps the previous owner was worried the gear /chain could wear the cover ?  or that the cover oil seal would not stay in the cover? ,    Is this  the charm of  owning  these old clunkers? lots of  mysterious puzzles to  ensure we don't have to watch Emmerdale or Coronation Street for entertainment?.

I have a cutaway cover that holds the shaft in position against the pull of the chain and is pretty essential to get the cam chain tension right , Norton stockists sell a bracket that does the same.The cam nut should not be very tight and usually a rap with a  hammer on the spanner works. Engine is held in top gear with back brake on and all nuts loosened before a strip down.

The play in both Timing Chains will allow the Intermediate sprocket to be eased forward a few mm. Hold onto the spindle while pulling the sprocket or it may drop out of its housing. A torch, small mirror and angled probe (bent wire) will then allow investigation of the area behind the sprocket.

Don't touch the camshaft nut without using a spindle support of some kind.  Remember that the crankshaft nut is a Left Hand Thread. If the pistons have been removed then a Tommy bar through the Conrod eyes plus a chunk of timber across the crankcase mouths will help with undoing the Crankshaft nut.

Yes if the intermediate spindle is loose in the crank case. IF the spindle came out when the outer case was removed, bingo washer drops out.

The spindle is usually a tight fit in the case and is not to be disturbed, however a few clumsy attempts to remove the cam nut  means that many are loose. Does not cause a problem appart from  the possibility that it will come out by accident when the cover is removed and can then allow the thrust washer to drop . A loose spindle may allow the chains to be removed a bit easier as normally  it all has to come off together as you have found,    Looking at your motor I would definately say  the mangler has been in there before you.