timing chain tension release with cover still installed.

[Giamanut]

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.

[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.

[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.

[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?

[Parzival]

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?

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.

[DMCVegas]

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.

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.

[Giamanut]

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.

Yes one side at a time and no engine rotation!

[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

[SpudMurphy]

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.

[Giamanut]

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

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.