hi keith,the spacer is supposed to rotate with the crankshaft
and the two bearing inners,so if you see a churned up one the bearings have locked at some time causing one or other inner race to spin on the crank.
if you make your own ,it will take the same time for either material ,so use what you have to hand.
cheers rick
email (option): richardholt@rocketmail.com
Hi Kieth..The original bearing spacer was not hardened but there would be no harm in doing so to make it more durable...I have thought of doing it myself. You will have to use a piece of silver steel and flame harden it after making it.
The spacer should measure 1.000"-1.005" long.
It is common to find wear on this spacer, even in engines that are running well and don't have bearing problems.
The spacer is locked between the bearing by the pressure of the engine shock absorber spring.
I think that over a period of time as the shock absorber operates there is a degree of 'fretting' between the parts as the spring pressure fluctuates, causing the wear......Ian
email (option): ian@wright52.plus.com
after writing it i realised there's no extra preload on the spring when the entire mechanism is moved the "nut to sprocket distance" remains the same 
But that wasn't the main aim anyway ....
Am I confused here? 
The spacer 66-660 is the one between the drive side bearings innit? So it has no effect on the clutch to engine sprocket alignment, or does it?
The other spacers outboard of the bearings and under the sprocket/shock assembly are different and do influence the alignment and it might be worth making up your own to ensure 100% alignment.
Just a thought though on the original post. How much spare time do you have? A new 66-660 costs 4 quid, surely the time spent making one would be better spent down the pub.
Cheers
Pete
email (option): petercomley@web.de
I never fit the tabwasher to the shock absorber nut. I tighten the nut all the way until it comes up against the end of the cush drive sleeve and then knock it up tight.I haven't had any problems with it loosening...Ian
email (option): ian@wright52.plus.com
Worth mentioning though Fred..
...Ian
email (option): ian@wright52.plus.com
I managed to scrounge a large pin from the company scrap bin
Thought it was hard, but its only mild. I would have liked to use something a bit harder than used in the standard part. never mind.
The OD of the roller bearing inner, excluding the champher, is about an inch and a half.
The OD of the ball bearing inner is approx 1.320", and the original spacer OD is about 1.310"
The height or thickness of the outer and inner bearing rings can vary a bit, depending on the brand.
I'll cut a spacer to about 1.320" OD, that should do it, but not after the pub though.
The excess I can use to make an outer spacer, and get the sprocket alignment correct in the process.
email (option): keithatkinson@hotmail.com
Hi Kieth..When you make the replacements note that the I.D. of the inner and outer spacers aren't the same..so don't bore the inside to the bigger size all the way through!...Ian
email (option): ian@wright52.plus.com
Inner and outer spacer I only see one, 66-660 plus a shim 66-661 (by the way, what thickness?)
Now I will pass a sleepless night
email (option): viaconsu # planet dot nl
Couldn't you just clean up the worn spacer in a lathe and shim it to the right size?
I must still have a few NOS spacers, not sure where I put them.
Henk
email (option): ahum@quicknet.nl
Hi Hans..There is one spacer inside the crankcases between the main bearings..and one on the outside between the outer main bearing and the engine sprocket carrier..I blame Fred for the confusion.. ...Ian
email (option): ian@wright52.plus.com
Not seen him for a while
I seem to remember someone saying that shimming the bearing spacer isn't a good idea as there can be some relative movement between the parts (see how the originals get battered) and any shims may break up and go walkies around the bearings. Or am I wrong.. again??
Cheers
Pete
email (option): petercomley@web.de
...Ian Sorry Ian, still can't find that second one. It doesn't show on the cross-section:
and on the exploded drawings I only see 111:
HELP !!
email (option): viaconsu # planet dot nl
Hi Hans..There are two types of 'carriers' for the engine sprocket when used with the '4 lobe' shock absorber assembly..One is a 'one piece' part and has the spacer machined onto the back (and therefore it is hardened) and the other type is used with a seperate spacer. The exploded drawing you have posted shows the one piece arrangement and the shoulder (or spacer) on the back of the sprocket carrier can be seen..but not as a sperate part....Ian
email (option): ian@wright52.plus.com
Yesterday my gearbox & entire primary side was removed, first time in approx 30years
Behind the inner cover I found a felt type packing in the crankcase immediately surrounding the bearing carrier on the crankcase, there are 3 deep cavities separated by reinforcing ribs
Is this normal to find ?
Must also check for this spacer located behind the Cush drive assy
Any ideas on the felt ? Prt no availability etc
Many thanks
Job
You mean these? These were obviously for weight reduction, to make the WDM20 more nimble in the field
email (option): viaconsu # planet dot nl
The last engine i put together was a 1938 "M" model, the 38 M20 has a different setup again to either of those, it uses a very short inner spacer & a long outer, almost a swop around of the WM20 setup, & that's actually where my confusion arrived from after seeing mention of an 1" long spacer i discounted the mid bearing spacer which on the one i built was only about 3/8" long.
They must have realised the outer bearing could be given an easier life by outrigging it into the unused space.
No John, never seen that in my WDM20, those cavities were empty. Have only seen that when I was young, and playing with my toy cars on a carpet, they finished full of felt-like stuff in the gears
But perhaps Ian knows more
email (option): viaconsu # planet dot nl
hi keith,how are you getting on with your spacers?did you check your bearings for obvious signs of damage ?is there any wear or
scuffing on your crankshaft journals?.
if you use a bit of carbon steel for your bush,you can heat it to a dull red and oil quench to toughen it up.
i cant myself see why if everything is locked up why the spacer became churned up in the first place.anyway let us know how you get on.
cheers rick
email (option): richardholt@rocketmail.com