primary chain hydraulic tensioner assembly doesnt make sense

Esmerela

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Its a messy job trying install them, they want to extend out and oil leaks everywhere

Jimbo

You don't really need to try and go with fully primed wet assembly, when the steel plate is fitted to the front of the tensioner if creates a well between the tensioner body and the back of the plate hence the gasket. You can fill this with oil and prime up the assembly by squeezing the slipper plungers, there are vent holes in the plungers to help purge some of the air.
If the bike has stood for a long time, with the aid of a syringe you can fill the well through case filler hole and prime by lifting and depressing the chain before stating.
 
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Esmerela

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Due to the previous discussion I know the nylon plugs in my Mk3's plungers are fitted as shown on the AN drawing.

Both upper and lower plungers touch the tensioner body without becoming coil-bound so something must have changed.

SDC13295.jpg


SDC13296.jpg


SDC13292.jpg


SDC13293.jpg

Hi Lab

Looks like that chain or one of its predecessors has been lunching on the inner primary cover at some point.
 

jimbo

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I looked at my spares, one plastic piece looked to have some kind of glue on it and the knob end seemed to be forced into the spring. The only spring I had was kind bent out of shape after messing with it a while I got it to go into the plunger bore. Installed both ways the spring and plastic piece inserted into the body could be compressed flush and pushed all the way in. When assembled correctly ,the knob on the plastic piece away from the bottom of the plunger it was obviously stiffer but not too bad.

DSC09961.JPG
DSC09955.JPG
DSC09956.JPG
DSC09957.JPG
DSC09958.JPG
 

BritTwit

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It almost appears that the spring end may have over-worked the plastic cap and machined/cut the plastic cap material enough to allow the spring to slip over the cap region and slide down the plastic shaft.

dsc09957-jpg.jpg
 

jimbo

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It almost appears that the spring end may have over-worked the plastic cap and machined/cut the plastic cap material enough to allow the spring to slip over the cap region and slide down the plastic shaft.

Could have, it almost looked like it was melted. However that messed up piece probably just confuses the real issue, and we should probably disregard it.
 

BritTwit

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The MK3 manual diagram doesn't help much either, except that there doesn't appear to be a cap end of the plastic rod facing toward the tensioner.
This may imply that the cap end should face the spring.

2v2EiBRugxAn6Wm.jpg
Hosted on Fotki
 

p400

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in the shop just now,
coil bound length of the spring is 1.00"
depth of plunger tube is 1.670"
length of plastic piston is about 1.00"

What is the depth of the bores in the tensioner alloy body?
I don't have one out right now.

don't tell me this is wrong way, it is just for measurement.


20190517_tensionerAssembly22.jpg
20190517_tensionerAssembly33.jpg
 
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jimbo

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What is the depth of the bores in the tensioner alloy body?
its 13/16", your assembly will not fit flush( the bottom of the tensioner alloy body hole is tapered, and would show a little more depth if measured from the center) However your new white colored plastic spacer seems longer then my old unmangled discolored one.

correction it should be 1 13/16"
 
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L.A.B.

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coil bound length of the spring is 1.00"

My tensioner springs = 0.83" Edit: And, spring wire diameter is 0.031".


depth of plunger tube is 1.670"

The two plungers of mine are slightly different:

= Internal parallel sections 1.86"/1.856"

External tubes 1.8"/1.78"

The compressed spring does not become coil-bound until fully inside the plunger tube with the nylon plug as AN's drawing.

length of plastic piston is about 1.00"

= Same.

What is the depth of the bores in the tensioner alloy body?


= 1.81"

SD1329.jpg


SD1330.jpg




"What is the depth of the bores in the tensioner alloy body?"

its 13/16",

1.13/16"? (1.8125")
 
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jimbo

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1.13/16"? (1.8125")[/QUOTE]

yes 1 13/16" that was a oops
 

jimbo

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p400 said:
depth of plunger tube is 1.670"
Click to expand...
The two plungers of mine are slightly different:

= Internal parallel sections 1.86"/1.856"

p400, you might have something in the bottom of the plunger tubes
 

p400

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It is quite obvious that we do not understand this primary chain tensioner, at all. or the replacement parts available for this device.
I am not meaning to confuse this issue. 2019-1975 = 44
Here are more pictorial data.
I am beginning to doubt the replacement parts.

My spring wire is 0.032" diameter wire, 29 coil count, 4" free length, 0.959 compressed coil bound

20190518_CompressedSpring1.jpg


20190518_PistonLength1.jpg

This picture is not well aligned, measuring outside edge diameter of piston to tail.

20190518_PistonVsPlungerHole1.jpg


20190518_PlungerTubeDepth1.jpg

this is the length of the plunger bore at the "shorter" outside edge.
this inside bore has a dished end that is slightly deeper 1.722"-1.724"

20190518_PlungerTubeLength1.jpg


plunger tube length externally
 
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L.A.B.

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It is quite obvious that we do not understand this primary chain tensioner, at all. or the replacement parts available for this device. My spring wire is 0.032" diameter wire, 29 coil count, 4" free length, 0.959 compressed coil bound


0.032" is 21 SWG and therefore, a standard wire size although mine seem closer to 0.031".
From my photo mine appear to have just under 26 turns.

1.648"

this is the length of the plunger bore at the "shorter" outside edge.
this inside bore has a dished end that is slightly deeper.

1.781"
plunger tube length externally


My 'RENOLD ENGLAND' plunger tubes are certainly longer internally so along with the extra spring coils it seems the replacement parts are the problem.
 

p400

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I was able to purchase what appears to be an NOS plunger with a 26 coil count.
not arrived yet.

PlungerEbay1.jpg
 

jimbo

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FYI, I had the plastic piece with the button in the bottom of the plunger, the wrong way , it worked fine( had some slap maybe it will be better when I assemble it the "right" way).
 

p400

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received an NOS plunger kit, on the left -
spring is different
white plastic piston is different
steel/rubber plunger is different

Andover used pieces on right


20190522_190456.jpg
 
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