Can you manually adjust the tensioner to take a little of the slack out?

I'm actually thinking of starting a new topic asking specifically about tensioners - I've done several cam changes over the years - but have only just for the first time done it by locking the tensioner with an Allen key (in the past I've always gone the remove it completely then slide it in followed by the retainer etc. - making sure the pins are into the slot but not locking or releasing it as such).

Locking it and then releasing it are not a problem - but doing it this way makes me realise the tensioner IS actually designed so you CAN preload it: - ie. If you look at one out of the vhicle the back face of the slots in the inner housing have steps... - once installed, after you unlock it by turning the key clockwise to release the pins from the steps on the smooth side of the slots, you can then keep turning clockwise until you encounter resistance - keep going a tad more against the resistance and it'll "click" - this is the pins inside the plunger camming over the notches in the slots - and voila there's preload.

What I'm wondering is whether this is ok - I CAN well imagine going more than one click might be a very bad thing but is one click ok???

I'm sure the workshop manual makes no reference to preloading it.

Im pretty certain with the pre-tensioner you just un lock it and it tensions as much as it can (sometimes the full way). And when you fire it up oil pressure pushes it right out.

I've just done headgasket vrc kit and timing chain kit and it cost me only $135 for the full timing chain kit. !

Yeah, once the tensioner is unlocked then the spring will push it out and apply light preload - then oil pressure - once there is oil pressure - will apply full operating tension. In fact it should still all work fine WITHOUT unlocking it as all unlocking it does is put it under light spring tension - the danger is that during the initial startup - especially if the engine doesn't catch straight away - then the pluger can end up flicked back into the bore and rotate so the end of it doesn't engage properly when it does get pressurised out. Even so it'll still work - with the side edge of the end section pushing on the chainguide. Dangers then are that the pluger might twist and "drop" the chainguide into the end notch properly while the engine is running, which could conceivably cause the chain to whip due to momentary loss of tension - or because the chainguide isn't located properly in the plunger notch, it might wobble about and break.

I've actually had a mechanic put my engine back together and screw the pooch with the tensioner - evidently put it all back in without locking it but the pins weren't lined up with the spiral slots in the sleeve - so the sleeve was compressed and busted - I didn't even know anything had happened until the next time I pulled it out to change the cam months later and the sleeve came out in two main pieces plus small handful of metal fragments and shavings. I ended up putting it all back in with just the plunger and spring and it ran fine like that for at least a year.

My point is that the stepped side of those spiral slots in the sleeve seem to be there so as to apply pretension - ie. by gently turning the allen key clockwise until it "clicks" - but no one seems aware of it specifically as something that needs to be done. My worry is that it's something that was a nice idea at the design stage but didn't work out in practice - but instead of redesigning the tensioner - ie. removing the sleeve or at least removing the notched steps - Ford just doesn't mention using the pretension.

I might be wrong about that tho - from MEMORY there's no mention of pretensioning in the workshop manual but it might well be there. I imagine it would be something along the lines of an instruction to use a torque wrench to apply a light torque in the clockwise direction with the special tool.

Those notches DO work to limit the amount of plunger travel when it's pushed on from the chain side without oil pressure (is the whole reason for needing to lock it compressed in order to be able to get the cam gear back on) - so that may be the whole reason for them and I might be barking up entirely the wrong tree as far as pretensioning goes...

I'm in the process of putting my engine back together after doing the head gasket - I've clicked my tensioner so will see how it goes and report back. With it "clicked" it's not like the chain is TAUT - there's still some deflection in it with gentle pressure.