Hi folks,
Have any of you Twin officianados got a couple of late A50/65 Crankshaft items lying around gathering dust? They are:-
68-0685 Crankshaft Thrust washer (this is the one that sits on the timing side has 4 'ears' on it and a bronze coating)
68-0638 Crankshaft Shim Retaining Cup. (fits drive side between roller brg. and Crankshaft and holds the shims)
All the excellent dealers can't help with the latter, Draganfly have the thrust washer but is very expensive.
Reason for needing these is on splitting the crankcase to check the 0.045" endfloat all these were missing!!! The expert who rebuilt the engine after the excellent crankshaft regrinds must have forgotten and not read the manual, Arghhhhhhh!!!
Please help me get my blood pressure down,
Chris
HI CHRIS
I HAVE A SHIM RETAINING CUP FOR A65 YOU CAN HAVE FOR FREE IT IS USED
IF YOU PM ME YOUR ADDRESS I WILL SEND IT TO YOU FREE OF CHARGE > I WAS
LUCKY FINDING THIS ONE AS THEY SEEM HARD TO GET NOW > GOOD LUCK WITH
THE REBUILD REGARDS JOHNBOY .
:)
Just as a matter of interest I got a couple of shim cups from USA. They were running out of stock.
Mike 8) 8) 8)
Have you tried Kidderminster M/C's ?
Hi folks,
Fantastic response. Yes I tried Kidde and C+D plus others websites who were showing no stock. However, thanks to Johnboy above and another member I've located the parts and all sorted thanks.
This is what being a member of such a great club like ours is all about!
All the best
Chris
:)
I would like to hear the outcome when you put it back together with the shim cup fitted.
I put the correct shims and cup in mine and as soon as I bolted it up the crank was absolutely solid.
I understand that the thrust washer wasn't always fitted.
Another point that I have discussed with a couple of engineers is reference the end float. As the jornal is an interference fit in the bearing you shouldn't be able to feel the end float. If you are able to move the crank laterally by hand it points to the crank being loose in the bearing which may well result in the jornal turning inside the inner bearing spool with resulting damage.
I write this in the hope that it will extend my knowledge not as an effort at being a smart donkey.
Mike 8) 8) 8)
Quote from: Mike Farmer on 31 Jan, 2019, 16:01
:)
I would like to hear the outcome when you put it back together with the shim cup fitted.
I put the correct shims and cup in mine and as soon as I bolted it up the crank was absolutely solid.
I understand that the thrust washer wasn't always fitted.
Another point that I have discussed with a couple of engineers is reference the end float. As the jornal is an interference fit in the bearing you shouldn't be able to feel the end float. If you are able to move the crank laterally by hand it points to the crank being loose in the bearing which may well result in the jornal turning inside the inner bearing spool with resulting damage.
I write this in the hope that it will extend my knowledge not as an effort at being a smart donkey.
Mike 8) 8) 8)
I have wondered that as well is it only when a roller main bearing is fitted you will get endfloat? although with the other end in a bronze bush it wont move either.
Are there not dimension marks on the crank that tell you what shims to fit? maybe i am talking rubbish! ???
Cheers
derek
HI CHRIS
YOUR SHIM CUP HAS BEEN POSTED > COULD YOU LET ME KNOW WHEN YOU RECEIVE
IT PLEASE > REGARDS JOHNBOY
:)
Yes there are markings on the crank case and the crank. Put simply there is a mark on there case something like .810 and likewise on the crank .791. Take one from the other= .019. Maximum allowable is 2 to 3 thou So .019 minus 3 thou =.016 therefore put 016" shims. Those figures are straight from the manual.
Mike 8) 8) 8)
Hi Derek and Mike,
Yes, it is only the later, post '65 or is it '66 where they fitted the shims. They didn't need to when it was a ball race.
The end float is the clearance between the lip on the outer race of the main bearing and the rollers so needs to be a small as possible.
The result of having no shims and thrust washer, apart from the excessive end float was a knocking which was audible when the bike was ticking over and was definite when putting a screw driver to the ear and rotor cover, but not the crankcase itself. Also, the crank was rubbing against the two thrust washer retaining lips in the timing side crankcase which wouldn't do the crankcase any good in the long term.
Hope this helps
Chris
excellent thanks for the info :D
:)
Ok, I'm upsides with this so far and any comments I make are not intended to cast nasturtiums on any previous posts.
I have two A65 motors in pieces on the bench at the moment. 1963 and 1965/66 with the newer timing side bush. Both have the shim stamps on the cases and crankshaft.
I have looked at all the drawings that I could find and they all show shims in place from the very earliest engines.
THe way that I understand it is that the shims are there to centralise the crank so that the conrods run at exactly 90 degrees to the big end jornals. which means that the conrods move up and down exactly parallel to the bore. Thus producing even running and even wear on the B/E and S/E bearings.
I would suggest that once the crank is fitted into the drive side bearing and the spacer,. primary gear and alternator are fitted and tightened any lateral crank movement is absolutely minimised.
I am wondering if the replacement main bearings are causing grief.( I shall do some medgering once its warmer in the shed)
Over to someone more knowledgeable.
Mike 8) 8) 8)
@Mike
Ignore my previous post about bronze bushing being tight the crank should be able to move laterally in the bush, BUT not in the primary side bearing if a conventional ball is being used.
If a roller bearing is fitted the lateral movement has to be taken up by shims.
Have you got a roller bearing fitted? and if yes are the shims correct.
if using a ball bearing primary side without shims and its locking up is it correctly home against the bearing and housing, seal etc
;)
derek
:)
:) :)
HI Derek
Just thought that I would put these pics on to show what bearings I am using.
Mike 8) 8) 8)