Lifters/Rockers as maintenance replacements?

greiswig · **Posted:** Wed Sep 10, 2014 4:06 pm

Posted this in the middle of another thread, where it just threatened to derail things. So...

I am really debating whether or not to replace my rocker/lifter set. My engine has 140k on it, and a leak in the cylinder head. My oil change interval has been about 3500 mi. consistently, using Mobile 1 5W-40. I put an SEGR in very early...about 10k miles, if I remember right. I looked at each lifter as they came out, and other than the sketchy little clip that holds the rocker to the lifter itself, everything looks great on all of them: the bearings roll easily and without apparent play or slop or spalling, and the wear where they hit the valve stem is more like a spot of polished metal. The lifters pulled out of the bores smoothly, and don't show any scoring that I can see.

Peace of mind is worth a lot to me, but I just don't have a lot of spare funds right now what with having to repair/replace this head. I'd rather avoid putting more money on a credit card if I can help it.

What are the common failure points for the rockers and lifters? I'd hate to drop $370 on new parts that are only 3-5% better than what I already have, especially if I should only reasonably expect another 100k out of this vehicle anyway. Mind you, I had it in mind that a diesel ought to get more than that, but...hey, time to be realistic.

thermorex · **Posted:** Wed Sep 10, 2014 4:28 pm

If you'll take the cyl head off, I'd say it's worth the peace of mind. You can check the map sensor with the torque pro, 18.2g/s are the stock, new engine values, measured at sea level with engine at operating temperature while idling. If you have under 17 g/s, it may worth replacing them, if you already took the valve cover off, even though 17 g/s is not a horrible value. It is probably a good thing to do if you take the head down to replace the gasket and check it for leaks, as is also good to go with arp studs.

Common wear points is where the roller is, soot will compromise the bearing, generate less lubrication and more heat, eventually seizing the bearing and causing the cams to contact the arm directly, not on the roller but in the arm sides.

Don't want to open an oil debate, but can't help saying something about oil... If you drive short trips, under 30 miles one way, with no towing, I'd consider using a thinner oil, like the "hated" 0w40. This one is more fluid when cold. The 5w40 diesel truck is great when you tow, or the oil goes past operating temperature (200+ degrees), if you drive the jeep as a regular car, the 0w40 is perfect. Fwiw, after about 20 miles of straight highway drive at about 65mph, in 70 degree weather, my oil is just a bit over 180 degrees, with pressure of ca 20 psi on idle. I use now 0w40. For the 3500 miles change interval, and no egr sooting the oil, 0w40 is better, I'd say you can go 5-6000 easy. Thicker oil is great when you tow, go on steep hills and want to keep your highway speed, on this conditions when the engine works hard, the oil may get to 220 degrees, even more. I compared both oils' technical data sheet, and as both are 40 weight, the 5w40 does better in such harsher conditions due to being thicker and having more proper additives for those conditions. It's a personal preference and a conversation that's always hot debate, but repeated data and oil analysis does not lie.

greiswig · **Posted:** Wed Sep 10, 2014 5:37 pm

Thermorex,

Thanks for the reply. I have the head off already. But that's what is killing my wallet. From what you say, if the roller bearings feel good and don't seem to show slop, I might be good for some time with what I already have? I wish I had a new assembly just so I could make some measurements.

Mike92104 · **Posted:** Wed Sep 10, 2014 5:43 pm

It sounds like you have been doing all the right things to protect your rockers. I say if they look good, the re-use them.

papaindigo · **Posted:** Wed Sep 10, 2014 7:14 pm

greiswig · **Posted:** Wed Sep 10, 2014 10:28 pm

Thanks, all. I'll give every one another once-over, but I feel a little better.

joelukex4 · **Joined:** Thu Sep 29, 2011 4:54 pm **Posts:** 386

[/quote]Don't want to open an oil debate, but can't help saying something about oil... If you drive short trips, under 30 miles one way, with no towing, I'd consider using a thinner oil, like the "hated" 0w40. This one is more fluid when cold. The 5w40 diesel truck is great when you tow, or the oil goes past operating temperature (200+ degrees), if you drive the jeep as a regular car, the 0w40 is perfect. Fwiw, after about 20 miles of straight highway drive at about 65mph, in 70 degree weather, my oil is just a bit over 180 degrees, with pressure of ca 20 psi on idle. I use now 0w40. For the 3500 miles change interval, and no egr sooting the oil, 0w40 is better, I'd say you can go 5-6000 easy. Thicker oil is great when you tow, go on steep hills and want to keep your highway speed, on this conditions when the engine works hard, the oil may get to 220 degrees, even more. I compared both oils' technical data sheet, and as both are 40 weight, the 5w40 does better in such harsher conditions due to being thicker and having more proper additives for those conditions. It's a personal preference and a conversation that's always hot debate, but repeated data and oil analysis does not lie.[/quote]

Once the engine reaches operating temperature both oils have the same 40 weight viscosity.

DOC4444 · **Posted:** Wed Sep 10, 2014 11:34 pm

I had a similar situation and decision to make. I had SEGR by 30K miles and GDE by 45K. Used Mobil 1 5W-40 in summer, 0W-40 in winter (though now using the Canadian Mobil 1 0W-40TD in winter). I had a new set of rockers on hand. Geordi felt the old vs new. He could not feel any radial play in the old. I could. I consulted with Keith and he favored replacing them. I replaced them. I would strongly suggest you order new ones and compare the two. These items are so critical, I would not reinstall ones that have any play. I do not think you will have any trouble selling them to someone here if you decide not to install. Not sure what ID's restocking charge is.

DOC

thermorex · **Posted:** Thu Sep 11, 2014 10:40 am

greiswig wrote:

Thermorex,

Thanks for the reply. I have the head off already. But that's what is killing my wallet. From what you say, if the roller bearings feel good and don't seem to show slop, I might be good for some time with what I already have? I wish I had a new assembly just so I could make some measurements.

You're correct, based on what you said, imo the rockers should be good. But I also agree with doc. Overall, if you listen to everybody in the forum, you'll get a brand new engine for your peace of mind, lol.

thermorex · **Posted:** Thu Sep 11, 2014 10:47 am

joelukex4 wrote:

Once the engine reaches operating temperature both oils have the same 40 weight viscosity.

In theory yes, but in reality no. 40 weight oils (or 30 or any other weight) do not have all the exact same viscosity. Spec sheet would have the centistrokes (cts) for each of them, usually for 40 degrees Celsius and 100 degrees Celsius. For example same brand of a high mileage X weight oil is thicker than a regular X weight oil. A Mobil 1 X weight oil may ha e a slightly different viscosity than a shell X weight oil. The difference is not much though.

greiswig · **Posted:** Thu Sep 11, 2014 12:13 pm

thermorex wrote:

You're correct, based on what you said, imo the rockers should be good. But I also agree with doc. Overall, if you listen to everybody in the forum, you'll get a brand new engine for your peace of mind, lol.

Well, given that I have no idea what the rest of the engine is like below the block, and given that I partially hydrolocked this one, I don't know about that 'brand new engine' part. :wink:

I'd love to think that might be true, but I'm too old for that.

I just went out and rechecked about 7-8 of them for radial play. Axial play, there's quite a bit. But I can't really feel ANY radial play.

So I picked one and put it in a vise, and rigged up a spring loaded dial indicator to it. I can measure between .001-.002" radial play as I push on the side opposite the indicator with my finger.

thermorex · **Posted:** Thu Sep 11, 2014 3:16 pm

Hard to say if you should replace them or not, I one can tell you for sure that I didn't feel any play, radial or axial, on the new rockers (didn't measure it, just trying to move them with my fingers), but also the rocker roller will break in a bit, so I am really not sure what to say about the play after let's say, 1000 miles. I wonder if Vm motori doesn't have some specs somewhere about this. Don't recall to be anywhere in the manual...

greiswig · **Posted:** Thu Sep 11, 2014 4:35 pm

thermorex wrote:

Hard to say if you should replace them or not, I one can tell you for sure that I didn't feel any play, radial or axial (snip)...

Really? No axial play? Mine have a lot! There seems to be nothing at all preventing the outer part of the bearing from directly contacting the rocker arm itself...except that there should be virtually no lateral load on it at all. There is a roughly .025" difference between the width of the roller bearing and the sides of the rocker, so oil can get into the needles. Mine all move freely within that gap, and it is very consistent from one rocker to the next.

Are you talking about a new set of rockers, thermorex? I wonder if they made a design change? If the bearing wears against the side of the rocker, throws some metal into the needles...I could see that being a bad thing.

Mike92104 · **Posted:** Thu Sep 11, 2014 5:12 pm

greiswig wrote:

thermorex wrote:

Hard to say if you should replace them or not, I one can tell you for sure that I didn't feel any play, radial or axial (snip)...

Really? No axial play? Mine have a lot! There seems to be nothing at all preventing the outer part of the bearing from directly contacting the rocker arm itself...except that there should be virtually no lateral load on it at all. There is a roughly .025" difference between the width of the roller bearing and the sides of the rocker, so oil can get into the needles. Mine all move freely within that gap, and it is very consistent from one rocker to the next.

Are you talking about a new set of rockers, thermorex? I wonder if they made a design change? If the bearing wears against the side of the rocker, throws some metal into the needles...I could see that being a bad thing.

I'm starting to think you're just not going to be comfortable until you buy new rockers.

thermorex · **Posted:** Thu Sep 11, 2014 7:32 pm

greiswig wrote:

thermorex wrote:

Hard to say if you should replace them or not, I one can tell you for sure that I didn't feel any play, radial or axial (snip)...

Really? No axial play? Mine have a lot! There seems to be nothing at all preventing the outer part of the bearing from directly contacting the rocker arm itself...except that there should be virtually no lateral load on it at all. There is a roughly .025" difference between the width of the roller bearing and the sides of the rocker, so oil can get into the needles. Mine all move freely within that gap, and it is very consistent from one rocker to the next.

Are you talking about a new set of rockers, thermorex? I wonder if they made a design change? If the bearing wears against the side of the rocker, throws some metal into the needles...I could see that being a bad thing.

I was talking about the new rockers. I do not recall them having axial play, nor radial play. Again, I just tried with my fingers, so that's not a scientific measurement.

kjjet · **Posted:** Thu Sep 11, 2014 7:55 pm

The only place you need to be concerned with is the rollers. If they move up and down even the slightest replace it. You could replace just the worn ones. Since you had a SEGR installed since 10k you saved your engine. NICE JOB. If they are not worn, they will go another 100k maintaining the way you are.

Good luck
KJJET

thermorex · **Posted:** Thu Sep 11, 2014 7:55 pm

Mike92104 wrote:

greiswig wrote:

thermorex wrote:

Hard to say if you should replace them or not, I one can tell you for sure that I didn't feel any play, radial or axial (snip)...

Really? No axial play? Mine have a lot! There seems to be nothing at all preventing the outer part of the bearing from directly contacting the rocker arm itself...except that there should be virtually no lateral load on it at all. There is a roughly .025" difference between the width of the roller bearing and the sides of the rocker, so oil can get into the needles. Mine all move freely within that gap, and it is very consistent from one rocker to the next.

Are you talking about a new set of rockers, thermorex? I wonder if they made a design change? If the bearing wears against the side of the rocker, throws some metal into the needles...I could see that being a bad thing.

I'm starting to think you're just not going to be comfortable until you buy new rockers.

I kind of agree with this, in a way, peace of mind is always important, and 370 is not a high price to achieve it. Keep old rockers, put new ones and scratch off one item on the worry list

Lifters/Rockers as maintenance replacements?

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