primary chain hydraulic tensioner assembly doesnt make sense

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p400 said:
It is quite obvious that we do not understand this primary chain tensioner, at all.
Click to expand...

This post most closely describes it's functioning:
https://www.accessnorton.com/NortonCommando/mk3-chain-tensioner-sprag-oil.16138/#post-234185

I understand quite well how this works and can probably, given enough time, write a description that more fully describes it's functioning.
The patent description is only the beginning basis for this MKIII device.
We all know the factory shop manual is of no help at all.
Might be a good topic for a tech session at the INOA rally .
I've been asked to give a tech session at the michigan rally.
In reality it starts monday and goes through thursday at site 74!
All invited to come by any time.
 
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here is a picture of the current Mk3 in my shop with Andover Norton pieces installed per diagram.
The upper and lower chain runs have the tensioner fully retracted.


primary chain hydraulic tensioner assembly doesnt make sense
 
So it appears to me that the original patent document shows the plastic part to be inserted into the spring, as it is on any other similar assembly, NOT the way the first drawing on this thread shows it.

Looks like whoever prepared the mechanical drawing for Norton got it backwards! :)
 
The resulting evaluation of this component clearly shows the tensioner bore depth deviated from the original Norton design as well as the spring length and rate. The main question is why did ANIL change them?
The nylon spacer is as original size and placed in original orientation.
Manufacturing mistake or did they reevaluate the design and attempt to alter the parts for different performance.
Until we hear back from ANIL, I would assume a manufacturing mistake and would not use them due to the difficulty in assembling them.
In P440 pix, I am not sure what he is saying. To me the #1 test is: can the upper/master tensioner be pushed in so the top chain run is flat (plus a little extra beyond flat) . The second test is: can the bottom/slave tensioner be pushed in so the bottom run is flat (plus a little extra beyond flat) .
If yes for both then it should function satisfactorily though altered from original.
If it does not pass both tests then I would only use original spec components or a fettled device.
 
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jimbo said:
FYI,installed the original plastic pieces with their heads toward the springs as determined to be correct. When riding the bike I cannot feel or notice any difference compared to when I had the plastic piece the wrong way. It might take a while for the plungers to pump up, but there is still some slap at certain times .
Click to expand...
after running for a while the tensioners are working fine with no slap , installed the correct way using correct original parts ( fyi I did replace the chain with new a while ago and that helped a little at that time)
 
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