5.9L and 6.7L Cummins Valve Adjustment.

Ajouté : 2026-05-05

[00:00:00]Hey guys, it's Cecila Queen here. Today we are going to be covering some tips and tricks when you are trying to adjust the valves. This is pretty much the same for almost every single Cummins truck.

[00:00:12]The valve lash specifications will differ with vehicles that have treatment, but for the for the most part, they're the same. The procedure is the same. Just make sure you verify your torque specs and verify your valve lash specifications. On this engine, it is 10,000 for the intake and 20,000 for the exhaust, which I will explain what that means in a minute. Um, how you get these trucks set up, obviously, you take the valve cover off, pretty self-explanatory. Um, if you have a 67 setup or a 2006 and later setup, uh, unbolting the valve cover gasket with the wiring harness is helpful. If you don't have that, you can just unplug the harness.

[00:00:55]Um, it kind of helps to have it out of the way of your valves when you're adjusting them.

[00:01:01]And yeah, we'll get into the valve adjustment. All right. So, obviously, this is what your stuff looks like. All right. I already have this one kind of set up so you can kind of see. I prefer to use these because I feel like I can feel this a little bit better with that. Obviously, you can tell that is really [ __ ] loose.

[00:01:25]Um, see where's an exhaust? That just seems really loose. So, we're going to double check everything and go through everything and make sure. Like I said, the intakes are the short ones, the exhaust is the long ones, and intake is 10,000, exhaust is 20,000. Now, I have this already set to top dead center compression one. I actually got really lucky when I turned this engine off, and it was almost dead nuts on top dead center compression one. And now I'm going to show you what that means. So there's a difference between top dead center and top dead center compression.

[00:01:58]There's actually two top dead centers on engines. There's a top dead center compression and a top dead center exhaust. So what you want, it doesn't really matter which cylinder you start on, whether it's one or six. But for ease of easeability and to make it simple, if this is your first one, I would start with one. And so what you're going to do is you're going to turn your engine over.

[00:02:26]See that red mark on my damper?

[00:02:30]That that's the mark you're looking for.

[00:02:33]And you want that to be pointing straight up to the sky. All right. Now, when you do that and you point it straight up to the sky, it's going to be on either one or six top dead center compression.

[00:02:49]Uh what that means is either one or six is on its compression stroke. And that's what you want is it on top dead center compression because that means your valves are fully closed.

[00:03:01]All right. The and then to do the other half which I'll explain in a minute, you'll have to rotate the engine 180° or well the cam shaft is 180, the crankshaft is 360°.

[00:03:16]So you rotate that all the way full circle again to get to top dead center compression six if you're on one already. And how you can tell which one is on top of center compression is to wiggle both valves and both of these are loose on cylinder one. Another way to check is cylinder one procedure when it's on top of center one is number two intake will be loose, number three exhaust will be loose, number four intake will be loose and number five exhaust will be loose. That is a good way to tell if you were on top dead center six. One of these might seem loose, but you don't want to touch it because that's on your exhaust stroke.

[00:03:58]If number six was on top dead center, you'd have one exhaust loose.

[00:04:03]or two exhaust loose, three intake, four exhaust, five intake and then both of them on number six would be loose. So we are obviously on top of center one. So we are going to adjust the first set which again to repeat is both of the cylinder one intake on two exhaust on three intake on four exhaust on five. All right. So, you might have noticed that I have little things on here. So, my exhaust one has a different key chain on it. This is something that I learned from an old tech to help keep these There goes my phone. to help keep these obviously keep you from mixing these up.

[00:04:58]So, We're going to that is obviously loose, right? So to break this loose.

[00:05:20]Your engine needs to be cold when you do this, by the way.

[00:05:25]So, what I like to do, this is kind of how I judge these, is I will turn this adjustment screw down. I like to set mine a little on the tighter side, but you want to drag on there. So, what I do is I set these slightly tighter than what I actually want them at.

[00:05:50]Because when you tighten this, even if you hold this still, it's going to loosen that up a little bit. So, I tighten them down a little bit more than I want them to be tightened.

[00:06:01]And then tighten down that.

[00:06:06]And if you do it right, you should have a nice, beautiful, slightly snugish drag. If you can't move this at all, it's too [ __ ] tight. If you don't have enough drag on it, it's too loose.

[00:06:20]And then we're going to do the same. I like to leave these fueler gauges in the last valve that I did just to help, you know, feel because you want them to be as consistent as possible.

[00:06:40]20,000 for the exhaust.

[00:06:48]Make sure you clean off some of that oil.

[00:06:53]And again, I'm going to make sure this jam nut is loose enough for you to do this.

[00:07:02]I'm going to feel it out.

[00:07:08]Get a little bit too tight.

[00:07:10]Then I'm going to snug this down.

[00:07:16]You can use ratchets.

[00:07:19]I don't like using ratchets with Allen's sockets on them. I don't feel like I can feel it as good.

[00:07:26]And that pretty good drag on that. And the most important thing is to keep all your valves consistent with how tight their drag is. So, we're going to do the rest.

[00:07:51]So, next we're going to move to intake on this.

[00:07:58]Now, it's not actually common for these to be this this loose. Um, but this engine is brand new and this cam shaft is brand new. So, that is common for a brand new engine. her fresh freshly rebuilt engine.

[00:08:53]Now, that's pretty good. But if if for some reason I didn't like how that one felt, you can do minute adjustments with this. Just make sure they're even. And you know, it can't be so tight that you're technically pushing down on that valve. And it can't be so loose that obviously then it would be another thousandth up. So, if you're checking these valves on an engine that's, you know, not brand new, there's a possibility that you're going to go and check these and it's going to be fine.

[00:09:48]Now, I've gotten fairly quick with these because I've done a lot of these, but there are definitely times when I just cannot get this to cooperate with the consistency that I hold myself to with my valves.

[00:10:08]that I will sit here and redo them until they feel perfect. And it's better to do that than it is to [ __ ] do a halfass job on your valves and have it run like [ __ ] The consistency of your valve job will determine how well this engine runs. All right, I'm going to finish with intake on four and exhaust on five since you can't really see those. and then we'll I'll touch back base with the camera or you guys when I go to top dead center six. All right. So, we finished top dead center one. Now, we're going to turn the engine over.

[00:10:58]And you can only turn this engine clockwise from as viewed from the front.

[00:11:05]So, if you pass I mean technically you could try to turn it the other way, but you're not supposed to. If you are turning this and you go too far past that mark that I showed you earlier, you need to go all the you need to turn you can turn it back if you can get it to turn back without loosening the bolts past where you want it and then turn it forward again.

[00:11:29]So, there's the mark, which actually I made that mark because I could not [ __ ] see the one that is stamped into the timing cover or into this. So, there is a mark there that says has a mark and it says zero, which means top dead center zero. I made it red so I could see it better. Um, I also verified this timing mark when I had the timing cover off and I can see the gears, but that's what the mark looks like. So, I'm going to keep turning it around until it's facing up again.

[00:12:04]And that will be top dead center six.

[00:12:08]So, turn it over and we'll start from there.

[00:12:41]It's pretty close. All right. So, now that I have it turned over 360°, right, all the way around.

[00:12:48]So, now you can see both my valves and cylinder one are tight now, right? Then here you go.

[00:12:58]That's loose. That's loose.

[00:13:01]Some of these might also be loose depending on what part of stroke is. But the main thing is to we're on top dead center six. So we want these to be mostly tight or at least, you know, depending on which direction of the stroke it's on. These are usually going to be mostly both tight. And then number two, we want the exhaust on number two to be loose. the intake on number three to be loose. The exhaust on number four to be loose. As you can see, that's on a intake stroke.

[00:13:33]Exhaust and then intake.

[00:13:38]And then you're not going to be able to see this, but both of the valves on cylinder six are loose.

[00:13:45]So that means you are on top dead center compression number six. And you can run the second half of the valves. And then after you are done with that and you are satisfied with your adjustment, then you can torque these.

[00:13:58]And then you can put your valve cover gasket back on, which I know this is a 2005, but I have a 2006 valve cover on it and a valve cover gasket. So, put all that [ __ ] on, bolt it down, and you're good to go.

[00:14:15]Okay.

[00:17:32]The last thing I'm going to tell you guys is obviously your torque spec is going to depend on what type of valve cover you have and what year it is. But always start in the middle and work your way out. Especially if you don't have a billet aluminum valve cover. It's very important. And especially if you have your wiring harness in your [ __ ] valve cover. It's very important to get that right or in your valve cover gasket. It's very important to get that right. So, yeah. Here you go. All right. So, now we are done with the valve adjustment and we're going to start it and see what it sounds like.

[00:18:11]Oh, by the way, before you go to start it, make sure you don't forget to uh take your breaker bar off the crankshaft.

[00:18:23]HEAT.

[00:18:45]HEAT.