push rod problem

[JohnK]

This is the second time that #1 cylinder push rod has been destroyed.  In the same way, both times.  You can see the pushrod cap is now attached to the rocker arm and I'm running on three cylinders.  I replaced this rod only earlier this summer and the Willys probably only has 5 miles on it. Is something going on down in cam?  The rocker arm?

[JohnK]

So I removed the #1 and it looks exactly the same as the second picture above from earlier this summer.  Long ago, when I dissassembled the engine, I bent one of the push rods.  I ordered a new set of 4.  When I rebuilt it, I used the original 3 and a new one.  Could it be that I don't have the correct replacment rods and the head of the rod is getting suck in the adjusting screw. The head separates from the rod and then the rod just gets pounded down.  The adjusting screw was locked down in position where I put it when I set the valve lash.

[Rus Curtis]

What caused the original rod to bend?  If you just used a replacement rod on that and noticed (instead of bending) you're seeing the separation of the cap, I'd guess there may be a difference in the old original rods and the replacements.  Could be that the original was more stout and instead of separating, it bent.  This is just a guess.

But what's causing this.  I don't have a clue on why the cap is sticking to the rocker arm.  Have you noticed a difference of the caps (comparing to the original ones you still have) or the rocker arms themselves?  Could there be some wear of some type?

If I remember correctly, those rocker arms are just dropped into the hole (not attached) but still wonder if you have anything going on with the valve or could there be something in the hole interfering with travel?

This is weird.

Maybe get a couple dozen of the push rods and just change it out with the oil change....

[SteveKfl]

Are there signs of equal lubrication of the four, or is possibly #1 dry?  We often hear tales of "replacements parts" NOT up to "proper specs", fitment, or strength.  Maybe swaping out one of the originals to there?  Good Luck!

[JohnK]

I bent the rod trying to remove the head without pulling the rods.  So it wasn't mechanically bent, instead ignorantly bent.

Tlhere are no signs of lack of lubrication but I will inspect it more closely today.  The rod caps look slightly different and I believe I got them at rockauto instead the usual - KW, Walcks, etc.  But today I'll have to shop in Austin.  I suppose a stuck valve might cause it - I'll make sure that valve is moving. "Yes, please change the oil and number one push rod please".  Not hard to tell when that happens, quite a racket.

Maybe I will put the new rod in #2 and move #2 to #1 - that's a good idea.  Thanks Steve and Rus for the ideas.

[JohnK]

No in stock rod to be found in Austin.  Checked auto parts stores and even Jeep dealership.  They all told me to order from KW. 

I ordered the NOS one from KW - twice as much but hopefully better fitting.
I won't be here when it arrives.  Hmmm, I'll set the lash on 1 and let my son finish it up.

[JohnK]

Always good to let things percolate over time - even if you don't like outcome.  My thoughts....

1) Two separated push rods is not a problem - it is a symptom. 
2)  It is somewhere else in the # cylinder valve operation - \
     a) value - new
     b) valve guide - new
     c) rocker arm - used
     d) tappet - used
     e) camshaft lobe - God forbid - brand new old stock from Debella

3)  I need to create my own diagnostic procedure
         1) observe and compare movement of #1 tappet vs good one when engine is rotated - tests camshaft lobe and tappet
         2) observe and compare valve movement on rotation of engine - tests valve , rocker arm
         3) rocker bushing - ?
         4) valve guide - ?

I appreciate any comments on what I may be missing or thoughts on my procedures.  I am really hoping it isn't camshaft or tappet because I'm pretty sure I'm pulling the engine for that.  While I've gotten good at that, I really don't want to do it for the 4th round trip.

[JohnK]

More thoughts....

1) Rods were not bent but instead the cap is sheared off -so valve is likely operating
2) I was concerned about a "wiped lobe" but all that will do is reduce how much the valve opens
3) I set the lash twice (once for each rod) and the locknut was still set - presuming I did it correctly
4) the rod cap lodged both times in the rocker arm adjustment screw meaning that's where it was when it sheared off

My conclusion : The cap was sheared off when the rod was under maximum vertical pressure when the valve was opening. So at that point , a force was applied to the rod cap while the tappet was on the lobe nose - and that force was not vertical but instead horizontal, and the rod was not designed for strength in that direction - so it sheared off.  It is only happening on #1.  Something is worn up top near #1. Closely examine the rocker arm, shaft, and support nearest to #1.  All used parts.  My service manual is in Austin, I'm in Cleveland - anyone know the procedure for checking the rocker components?

[Rus Curtis]

John,
I like your approach to this.  It has to be something.  I'm up to my elbows right now but did a quick look at the SM.  Para E-77. Inspection and Repair, covers the rocker arm.  I've never had a problem with mine so I've never disassembled it.

But.  Here's a digital copy (good for travel! lol)

http://48cj2a.com/images/manuals/UniversalServiceManualForJeepVehicles.pdf
(big download, 56MB and 281 pgs)

To paraphrase the inspection part, it seems to concentrate on cleaning the shaft and oil holes.  Ensure they're open and the shaft isn't worn or bent.  It then moves to the adjusting screw holes and if needed chase the threads.  Replace the screw or lock nut if either are damaged or deformed.  Same for the hole in the top of the rocker arms.

I actually like the idea of swapping your #1 with one of the others, i.e. #2 rod.  To me this would be an easy shade tree check to see if your problem is with the replacment rods or, in fact there's something wrong at #1.   Could be both.

If you find the problem is with the rocker arm assembly, I'd suggest contacting Harry Sheets for original parts (including rods):

http://www.midwestwillys.com/

[JohnK]

Thanks for the info Rus.  We will closely inspect the entire system. I ordered a new NOS from KW.

For all that thinking I've done, now I don't think any of that is the problem!  Yesterday I remembered that I don't throw anything away and while the Willy's isn't here with me, the bent rod is along with the remaining two replacement rods from the set of 4.  I obtained the replacement rod set from RockAuto.  Their catalog listed these as fitting the 58 f-head when I bought them.  However, now they only show the part number fitting a 2.2 cj-5, 6 from 68 on.  I pulled my caliper out - the original rod is .1" longer, the cup is .015" wider and .015" deeper.

I think I've found the problem.

[SteveKfl]

Yep, "formerly good supply sources" for "original-specs parts" are being "generically-computerized-inaccurate data-bases" leading to "errors for the customer's expense/damages/stress".  Rockauto Supply listed my "Willys DJ3A 4-lug drums" as the same "fit my model" as CJ's 5-lug drums 'pictured', for just one example???  KW took over Walcks, and now that "formerly good source" also has been "compromised" for "accuracy for DJ parts". 
 
Welcome to the could-care-less push-button sales approach, like at McDs, where THEY are now being proposed to be rewarded with $20/hr minimum wage (Ca) for "minimum effort and knowledge", and SILL can't get an order correct???  "Caveat Emptor" never took a "deeper meaning" that currently... IMO and from my experiences.  Sad to watch evolve the quiet but hostile "digital takeover".
 
I'm glad you found the "problem" and shared your experience.  Happy New Year to ALL!

[JohnK]

You're right Steve, trust but verify.  Now I know why Oldtime always suggests NOS.

If you look at this pic where I put everything together, click the pic to zoom - you can see the different rod in #1.

https://www.mywillyspics.com/image/j4Xcy

[Rus Curtis]

That DOES look different.....

[oldtime]

Sorry I’m late to log in here.
Yeah I agree Rus how can it possibly be right if it does not even look the same ?
Apparently that big upper cup is allowing side motion …