primary chain hydraulic tensioner assembly doesnt make sense

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jimbo said:
Its a messy job trying install them, they want to extend out and oil leaks everywhere
Click to expand...

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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L.A.B. said:
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.

primary chain hydraulic tensioner assembly doesnt make sense


primary chain hydraulic tensioner assembly doesnt make sense


primary chain hydraulic tensioner assembly doesnt make sense


primary chain hydraulic tensioner assembly doesnt make sense
Click to expand...

Hi Lab

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

primary chain hydraulic tensioner assembly doesnt make sense
primary chain hydraulic tensioner assembly doesnt make sense
primary chain hydraulic tensioner assembly doesnt make sense
primary chain hydraulic tensioner assembly doesnt make sense
primary chain hydraulic tensioner assembly doesnt make sense
 
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.

primary chain hydraulic tensioner assembly doesnt make sense
 
BritTwit said:
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.
Click to expand...

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.
 
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.

primary chain hydraulic tensioner assembly doesnt make sense
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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.


primary chain hydraulic tensioner assembly doesnt make sense
primary chain hydraulic tensioner assembly doesnt make sense
 
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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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p400 said:
coil bound length of the spring is 1.00"
Click to expand...

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


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"

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.

p400 said:
length of plastic piston is about 1.00"
Click to expand...

= Same.

p400 said:
What is the depth of the bores in the tensioner alloy body?
Click to expand...


= 1.81"

primary chain hydraulic tensioner assembly doesnt make sense


primary chain hydraulic tensioner assembly doesnt make sense




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

its 13/16",
Click to expand...

1.13/16"? (1.8125")
 
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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
 
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

primary chain hydraulic tensioner assembly doesnt make sense


primary chain hydraulic tensioner assembly doesnt make sense

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

primary chain hydraulic tensioner assembly doesnt make sense


primary chain hydraulic tensioner assembly doesnt make sense

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"

primary chain hydraulic tensioner assembly doesnt make sense


plunger tube length externally
 
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p400 said:
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
Click to expand...


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.

p400 said:
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
Click to expand...


My 'RENOLD ENGLAND' plunger tubes are certainly longer internally so along with the extra spring coils it seems the replacement parts are the problem.
 
I was able to purchase what appears to be an NOS plunger with a 26 coil count.
not arrived yet.

primary chain hydraulic tensioner assembly doesnt make sense
 
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).
 
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


primary chain hydraulic tensioner assembly doesnt make sense
 
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