timing chain tension release with cover still installed.

If you have to change head gaskets you do not have to remove the timing chain cover.
Zip tie the timing chains to the sprockets. when you back the cams out of the sprockets the tensioners will extend and keep the chains on the crankshaft sprockets.
to release the tensioner to reinstall the sprockets you can use a long pick. You need to feel for the hole in the front of the tensioner with the pick in place pull up while pushing in lightly on the chain guide. It will retract. You are putting your pick in the release screw slot and slightly rotating it counter clockwise by pulling up. You will know when you got it. Also on the Drivers Side you push down with you pick and on both side feel for the out board end of the slot. it may take a few attempts but it works. Use a long pick with a right angle tip and don't drop it.
Hope this helps. You can practice before setting the head in place.

You can also get a set of brackets to hold the sprocket in place, as well as dummy bearings & liner straps to rotate the entire crankshaft with the cylinder hears.

These tools still appear on eBay from time to time. I have 3 sets of these tools, and never paid over $30 for them. Usually they come from either retiring mechanics, or defunct Jeep/Eagle dealerships. Get yourself an Eagle Premier engine manual for the updated x-reference #'s for the same tools, and then use those to find them.

If you're changing the head gaskets with the timing cover still on, I think you can only do one side at a time. This will be a long process if you're taking your heads to a machine shop. You'd have to take one head in, wait until its done, reinstall it and then repeat the process for the other side. I would only go that rout if I were only changing the one side, at this stage in the game, if one of you're 40 year old head gaskets is letting go, how far behind is the other? Plus you can really clean and plate all your bolts and pulleys while you have everything off.

This is good information to have, of course, but imo, it doesn't take all that long to remove the timing cover, so why not just do it that way?

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Originally Posted by opethmike

This is good information to have, of course, but imo, it doesn't take all that long to remove the timing cover, so why not just do it that way?

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Well, removing the crank pulley nut can be a chore. I had to go out and find a low profile impact wrench, and even then it wasn't easy.

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Originally Posted by Parzival

If you're changing the head gaskets with the timing cover still on, I think you can only do one side at a time. This will be a long process if you're taking your heads to a machine shop. You'd have to take one head in, wait until its done, reinstall it and then repeat the process for the other side. I would only go that rout if I were only changing the one side, at this stage in the game, if one of you're 40 year old head gaskets is letting go, how far behind is the other? Plus you can really clean and plate all your bolts and pulleys while you have everything off.

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I see no reason why you wouldn't be able to remove both heads simultaneously. Granted you would need to secure the liners, but it should be quite doable. Now if your concern is that you need to rotate the cam sprocket to align with the cam itself and need to rotate the engine, then yes, you would need dummy bearings to allow the sprockets to rotate accordingly. And even then this is only if you opt not to remove the timing chains.

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Originally Posted by DMCVegas

You can also get a set of brackets to hold the sprocket in place, as well as dummy bearings & liner straps to rotate the entire crankshaft with the cylinder hears.

These tools still appear on eBay from time to time. I have 3 sets of these tools, and never paid over $30 for them. Usually they come from either retiring mechanics, or defunct Jeep/Eagle dealerships. Get yourself an Eagle Premier engine manual for the updated x-reference #'s for the same tools, and then use those to find them.

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I like tools but to be clear I was changing one head gasket at a time and did not need to rotate the engine, I think it is a lot easier without removing the timing cover. Just saying it is a useful trick in some cases.

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Originally Posted by Parzival

If you're changing the head gaskets with the timing cover still on, I think you can only do one side at a time. This will be a long process if you're taking your heads to a machine shop. You'd have to take one head in, wait until its done, reinstall it and then repeat the process for the other side. I would only go that rout if I were only changing the one side, at this stage in the game, if one of you're 40 year old head gaskets is letting go, how far behind is the other? Plus you can really clean and plate all your bolts and pulleys while you have everything off.

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Yes one side at a time and no engine rotation!

Are you re-setting the tensioner(s) the same way?
R.E. "Set both timing chain tensioners by turning the ratchet mechanism clockwise with a screw driver.", WSM C:07:11

My friend - a 71 year old retired Volvo Mechanic, said that he often wondered why there wasn't a "screw out access plug" in either side of the timing case, so that you could get to the tensioners without having to tale the whole front cover off. It would have cut down on time when performing these type of tasks.

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Originally Posted by Ron

Are you re-setting the tensioner(s) the same way?
R.E. "Set both timing chain tensioners by turning the ratchet mechanism clockwise with a screw driver.", WSM C:07:11

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No the screw they reference just turn enough to release the lock on the tensioner teeth they are just spring loaded as soon as you let go of it , it just pops back and lock on a tooth. the release screw does not turn all the way around.

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Originally Posted by Giamanut

No the screw they reference just turn enough to release the lock on the tensioner teeth they are just spring loaded as soon as you let go of it , it just pops back and lock on a tooth. the release screw does not turn all the way around.

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No, it's a ratchet mechanism...
Anyway, the tension needs to be set using the Work Shop manual's method (above, including "Do not assist the tensioner to find their operational setting") or the one in the Volvo Service Manual, Pg.56:

Attachment 61958

Otherwise, you are making a fairly high risk gamble, imho.

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For prosperity:
Attachment 61957

Quote:

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Originally Posted by Ron

No, it's a ratchet mechanism...
Anyway, the tension needs to be set using the Work Shop manual's method (above, including "Do not assist the tensioner to find their operational setting") or the one in the Volvo Service Manual, Pg.56:

Attachment 61958

Otherwise, you are making a fairly high risk gamble, imho.

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For prosperity:
Attachment 61957

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Exactly "do not assist" Yes it is a ratcheting type of assemble you don't but it adjust automatically a spring pushes it out notch by notch when you reach 4 notches your chains are worn out the screw is simply a release for the notches that allows you to push the shaft back in the pocket against the spring and as soon as you release it it comes back out the proper amount of notches that is exact why it states "DO NOT Assist " meaning don't push it against the chain to try and make your chain tighter.
They self adjust and the screw only turn 1/4 turn. Absolutely no rick of getting the tension wrong but you do have to make sure the chain in on the guides properly. Do Not Assist Literally mean self adjusting in this case!

Attachment 61960

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Originally Posted by Ron

Attachment 61960

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Yep the locking piece is spring loaded. The tensioner is also spring loaded.
The only way you can mess up the tensioner is by forcing it against the chain. IE Assisting it! Per the manual "DO NOT ASSIST". What adjustment are you referring to? Other than Do Not Assist? There is no real adjustment all you can do is release the lock and push the tensioner away from the chain, and as soon as you let go it is going right back against the chain and lock on whatever notch the slack in you chain allows. There is no adjusting that, per the manual.

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Originally Posted by Giamanut

Yep the locking piece is spring loaded.

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Yes, and that spring has it held in a "set or release" position (as called out above)!

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Originally Posted by Giamanut

The tensioner is also spring loaded.

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Yes, while the engine is off. And more so when the oil pressure pushes the piston...

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Originally Posted by Giamanut

The only way you can mess up the tensioner is by forcing it against the chain. IE Assisting it! Per the manual "DO NOT ASSIST". What adjustment are you referring to? Other than Do Not Assist?
...

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(Actually, removing the lock would mean replacing the tensioner, per the manual. Another subject ;-)

During re/assembly, when you "make sure the chain in on the guides properly" etc., you are 'assisting the tensioner' by reducing the up to 8mm play it's allowed to a minimum, which is ok. Applying pressure afterwards is not. Then they say to turn the tensioner's screw clockwise, moving it from the "release" position, which the ball and little spring are holding it in (per manual above), to the "lock" position, where the little spring and ball will then hold it (per manual above). It seems to me that you are skipping this step -- Nowhere do you adjust/set/turn the screw clockwise as called out in all of the manuals...

The way I read them all is, they basically want you to eliminate the play (w/o applying pressure) during re/assembly THEN ensure the tensioner screw is in its lock position/mode. An initial setting. Afterwards, the oil pressure will supply tension to the chain and the tensioner will advance (ratchet), taking up additional play. The piston is allowed up to ~8mm of play, but they want it all out whenever the engine is off.

:dunno: I do see that you might be able to use a pick to turn the screw just enough to release it a step but not enough to put it in the release position/mode, if you were very careful. And that it would probably take the slack back up the first time you ran the engine. But working blind with an unconfirmed <8mm = ~1/3" of slop and unconfirmed finger position would be beyond my comfort range, especially knowing that ignores several manuals saying to remove the cover and turn the screw clockwise.

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Originally Posted by Ron

Yes, and that spring has it held in a "set or release" position (as called out above)!

Yes, while the engine is off. And more so when the oil pressure pushes the piston...


(Actually, removing the lock would mean replacing the tensioner, per the manual. Another subject ;-)

During re/assembly, when you "make sure the chain in on the guides properly" etc., you are 'assisting the tensioner' by reducing the up to 8mm play it's allowed to a minimum, which is ok. Applying pressure afterwards is not. Then they say to turn the tensioner's screw clockwise, moving it from the "release" position, which the ball and little spring are holding it in (per manual above), to the "lock" position, where the little spring and ball will then hold it (per manual above). It seems to me that you are skipping this step -- Nowhere do you adjust/set/turn the screw clockwise as called out in all of the manuals...

The way I read them all is, they basically want you to eliminate the play (w/o applying pressure) during re/assembly THEN ensure the tensioner screw is in its lock position/mode. An initial setting. Afterwards, the oil pressure will supply tension to the chain and the tensioner will advance (ratchet), taking up additional play. The piston is allowed up to ~8mm of play, but they want it all out whenever the engine is off.

:dunno: I do see that you might be able to use a pick to turn the screw just enough to release it a step but not enough to put it in the release position/mode, if you were very careful. And that it would probably take the slack back up the first time you ran the engine. But working blind with an unconfirmed <8mm = ~1/3" of slop and unconfirmed finger position would be beyond my comfort range, especially knowing that ignores several manuals saying to remove the cover and turn the screw clockwise.

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Yes you can ensure the screw is turned clockwise you can also confirm the notches are locked and you can measure extension without removing the cover. But yeah make sure there locked before closing. Mine where easy. But as for comfort zone, I don't do anything I am not comfortable with neither should anyone else. Fact is you could describe this a hundred different ways and their will still be people that can not do it.

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Originally Posted by Giamanut

Yes you can ensure the screw is turned clockwise you can also confirm the notches are locked and you can measure extension without removing the cover. But yeah make sure there locked before closing. Mine where easy. But as for comfort zone, I don't do anything I am not comfortable with neither should anyone else. Fact is you could describe this a hundred different ways and their will still be people that can not do it.

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Now I'm confused. When I asked if you were re-setting the tensioner(s) the same way, you sad no and that they just pop back and lock on a tooth. Which I thought meant you were not resetting the screw at all (because it was done automatically). I.E. No mention of a different way to turn the screw back to "set", making it easy on yours....
Guessing from experience and assuming we're on the same page now, if one can, say, feel that the screw was moving from release to set and see that the mechanism ratcheted (without pressuring the chain ;-), I wouldn't see any red flags for most people already playing with the cam - As long as they understand that it needs to be done.
:cheers: