JohnEP

I am gessing that this is not "normal wear". Or is it? Are these reusuable? Mating surface on rockers looks the same (nice and rough). Must replace all pivots and all rockers? This engine was ran with coolant in the oil for about 800 miles. Could this be a sign that my lower bearings are also shot (eventhough they hold good oil pressure for now)?

JohnEP

CCKen

That's nasty looking. It looks like you weren't getting oil to the rockers.

Change all pivots and rockers. Be careful not to twist the bridges when removing and reinstalling them. Torque on the capscrews to 21 ft./lbs., with the associated piston at TDC compression.

Leave valve cover off and see if you are getting adequate oil flow to the top end through the pushrods with the engine running. If you aren't, the tappet(s) could be clogged or the bearings are shot.

JohnEP

All rocker pivots are similarly affected, so if it's clogged tappets/lifters, then all of them are clogged. When I last had it running (with clean 5W-30), the oil pressure stabilized at 19 PSI at idle (per dash gauge) after a warm-up idle, 3-mile spirited drive, and rest idle time. Could the coolant contamination have destroyed my pivots, while leaving my lower bearings intact?? Also note: the prior gasket I scarapped off was "Victor-Reinz" (non-OEM?), meaning that someone was in there before me. Could faulty installation of the rockers (over-tourquing) have caused this wear pattern?

Thanks,
JohnEP

diskman

That is due to coolant in oil.. Had a 2002 Dodge 2500 V10 that kept snapping the rocker bolts due to galling of the rocker surfaces like that. It really sucked.

I would guess that your mains, rods and cam bearings are in the same shape. Ouchie.

belvedere

I would guess so, too, but it seems strange that he still has decent oil pressure.

cruiser54

I agree.

Pull a pushrod or two and see if the hole is clear all the way through. .

JohnEP

All pushrods were beautiful, straight, with both ends shiney, and no clogs at all. I did "extensive" oil pressure testing (just with the dash gauge) before embaking on this project, betting on my lower half being OK. I was really bummed to see the rockers and pivots looking like this. So... could faulty install of rockers have caused this? (just tell me yes to keep me motivated to finish this project... heh heh...).

Thanks,
JohnEP

CCKen

Are all the rockers and pivots butchered like this?

Try reinstalling all the butchered rockers and check the rocker oiling with the valve cover removed.

Here's rockers oiling properly at just above idle. If you don't see this, say good night Gracie. If you do see good oiling, replace the rockers and pivots as I mentioned in post #2.

JohnEP

Yes; though I did pick the very worst of the bunch for this photo.

Excellent idea! I have the new head on, but not the exhaust or intake manifold. Big job (for me) to put everything back together to do this test. If I re-remove the fuel pump relay, and just crank the engine with the starter, should I expect to see any oil pumping up to the rockers? (It's winter here in Mich; I have fresh clear 5W-30 in right now.) Also, do I need to do the TDC installation for the "butchered rockers test", or just slowly torque each side of the bridge down?

Thanks again,
JohnEP

CCKen

Living in Michigan is no excuse..except for me.

Cranking the engine will get some oil up top but a significant amount to making any real judgement.

If you already have the new pivots and rockers then just install them and do the oiling check. I wasn't sure if you can comitted to buying them yet.

The FSM does not mention placing the respective piston at TDC to do the torque, I just surmised that it would be the thing to do (I did it) so there would be no load on the rockers. Actually, you should see the cap screws take up the lash in the tappets as you screw them down. With a good valve train you should see about a .040-.060" gap between the pivot and the head when the cap screws are just turned in finger tight, then draw up that lash when they are tightened down with a wrench. This would be difficult to see if the cylinder was not at TDC compression. If there is no lash at all (no take up from finger tight to torque) something is amiss. Either the tappet is shot or the push rod is too short. Keep an eye out for this when installing your new rockers. The 4.0 is a zero-lash valve train.

JohnEP

I graduated Belleville High 1988. Canton library was the best back then. Now, there's the internet...

My buddy is heading down to Parts Galore (Detroit junkyard) tomorrow for a different project. I asked him "any Jeep 4.0 or 4.2 straight six, any year": please get me a set of decent rocker assemblies. Shall I ask him to pull something for you as well???

First of all, my rockers all felt "rock solid" before I disassembled them off the old head. I know this is not a perfect test, but it is reassuring. Tonight, I reassembled one old rocker set onto the new head to see what you're talking about. Without turning the crank shaft, I simply chose the cylinder whose pushrods were lowest (and also equal in height). As I finger-turned the bolts on the rocker-assembly, the rockers closed firm against the pushrods and the valves. Then, I saw the gap between the pivot-posts and the head. This gap was easy to see, and roughly equal on both posts. Took ?1 full turn? with the wrench to gently close them.

Unless you see otherwise, I'm not inclined to worry about this or TDC when I install my (anticipated) "polished-with-age" junk-yard rocker assemblies. Really, I don't think I'd do anything about not seeing that gap at TDC anyways, b/c the new head is already torqued on the new gasket, and it is also tough for me to trust any of my lower bearing surfaces after seeing these torn-up rocker surfaces. To keep my spirits up, I keep reminding myself: I had 19 PSI oil pressure at hot idle before I started this project...

Your insights appreciated,
JohnEP

cruiser54

I think the TDC method is recommended for this reason:

There is a specified torque for the rocker arm bolts.
If, when tightening down the bolts, the valve spring is getting depressed while opening a valve, the amount of effort to tighten that bolt is higher. And, the added load can cause an unobservant person to tweak that bridge so it's no longer square, causing misalignment. Just be watchful and tighten the rockers that share the bridge evenly. .

CCKen

When you do install the replacement rockers/pivots, and bridges, make sure you put some grease in the pivot area of each rocker before installing the pivots. USE a torque wrench to tighten the capscrews to 21 ft. lbs. If you don't own one, O'reilly has them for refund/rent. Just make sure the torque wrench you use has 21 ft. lbs. somewhere mid scale on the torque wrench settings, not at the very bottom of the setting scale. Common torque wrench tolerance is +/- 4% mid scale, and no tolerance at the far ends of the scale. No telling what torque value you would be applying if you used a bottom of the scale setting. 21 ft. lbs. isn't much more than a firm handshake so be careful.

You may want to look down at the top of the tappets, with pushrods removed, to see if the oil hole in the pushrod seat in top of the tappets are crusted over. If they are you might try getting a 1/4" wood dowl and radius one end of it and use it, with some MMO, to twizzle (British term) around on top of the tappet to see if you can clean up the crust. FYI, the oil hole in the tappet pushrod seat is .095"

Do the oil flow check on the replacement rockers before closing it up.

JohnEP

I was really skeptical about the idea that the bridges could get "twisted" so easily. But lo and behold the twisted junk-yard bridges my buddy pulled for me yesterday:


Far right: you can see the twist on the "new" junk-yard part (gap above the table).
Far left: my old pivot for comparison (sitting nice and flat, but not so shiny).

I still don't understand how this twist can happen so easily. Perhaps this has something to do with my Belleville High education?
So humbled, I plan to rotate my crankshaft to get both rods "down" before I torque on each of these bridges...

Any easy way to knock off the "good" pivots to install on my old bridges? Any advice on how to choose which rocker to install on which pivot (he gave me a bag of loose parts)? Are the diagonal oil grooves on the pivot supposed to criss-cross the grooves on the rocker, or mate them (I'm guessing "mate" for max flow).

All the tappet seats that I could easily see looked nice and shiny. I used a narrow shop-vac attachment on all of them before installing the head (to help get out old gasket shavings). All rods ends looked perfect; also no wobble rolling them on my wife's granite kitchen counter top (much to her joy).

I'll use the old valve-cover gasket for a very short while, till I'm sure every thing is put back right. Then I'll run this test. Should I expect oil to be launched all over my engine bay during this test?

cruiser54

You can mix and match pivots and bridges at this point.

Told ya about tweaking the bridges......

Use the rotor to help you determine which cylinder is at tDC.