Broken Rocker Arm. Need Help

A simple valve adjustment just became a major pain. I guess I tightened it too much. I'll need to find a replacement but I have a few questions:

-Do I need to replace all 4 at once or can I just do 1?
-Anything else I should be replacing while I do it? Keep in mind... this is all a first for me.
-Any other helpful thoughts or things I need to know.


Thx in advance. My heart sank when it popped.

 

Oh and it's the #2 rocker arm. FWIW

 

Assuming this is an F134?

 

I'm a novice but I don't see why you couldn't replace just the broken one.

 

Yep!

 

Just wondering if the ease at which it broke might be a fluke or a sign of metal fatigue across the board. Also wasn’t sure if they all need to wear evenly

 

If you have the funds replace them all otherwise it'll keep you up at night.

 

Ok! Haha. I feel seen right now
Is it easy to remove the assembly? Anything I should be aware of in advance?

 

Just loosen all of them and take the whole rocker arm shaft off. Hope you can find parts, I have one, but I have two motors to, don't want sell my extra parts.

 

Make sure you get a wtb post in the classifieds.
Some people don't log on daily but have email notifications for the classifieds.

 

Copy that! I just ordered two of the right hand rocker arms from ebay. I also posted a wtb ad for the left hand ones in the marketplace. Hopefully someone has em as they seem to be on backorder everywhere else. I guess worse case scenario is I just replace only the broken #2 arm for now and Keep the jeep on the road while I search for the other ones.
I also just noticed that 3 of my pushrods are bent too so I ordered a set of 4 NOS rods from kaiserwillys. I wouldn't have noticed otherwise so I guess this all happened for a reason.

The jeep is gonna be really happy with the new rockers, new pushrods, a valve adjustment, a new manifold gasket (the old one had a leak which is why I had the engine side opened up in the first place) and a refinished/not rusty manifold! I really went down the rabbit hole with this one hahahaha.

Ok I'll pull the assembly today. fingers crossed all of the adjustment screws seemed to be too tight when I was measuring the .018 gap btw. Maybe that's the reason the pushrods were bent? No idea how that happened but they hadn't been checked since the P.O. owned it last year. It's a learning process for me working through everything in the jeep bit by bit.

 

I'd imagine that broken rocker could be welded.

 

Ok ya I'll keep it for future use just incase they become impossible to find someday. I don't know how to weld yet so it's an easier endeavor to just replace it.

 

Was the engine running when you adjusted the rockers?

 

When you adjust the valves, you need to make sure the lifter the pushrod seats in is off the lobe of the cam (back side from the lobe). You need to be sure you have the correct clearance at the valve stem before moving to the next valve. The lobes of the cam have tremendous leverage as you found out. This is also how pushrods can get bent too. You can roll pushrods on a piece of plate glass to check if they are straight. I have successfully straightened lightly bent pushrods. You can replace single rockers with no issues, but carefully check those that had bent pushrods for damage.
-Donny

 

Thx for this! I replaced the broken rocker arm and it went on without a hitch. I also just swapped out all 4 pushrods and did the "opposing valve" method to find the bottom of the lobes for the adjustment. All of my previous valves were set too tight by the PO so all but 1 of the intake valves was bent. Purrs like a kitten now. A bit "Tappier sounding" than I expected but I know theyre adjusted correctly. CHEERS!

 

The F134 should have the valvetrain sounding like a sewing machine!
-Donny

 

Valve adjustment was not done properly before which is how you got bend push rods and broken rockers. They were too tight.

You didn't describe how you adjusted the valve lash, and saying "I know they are adjusted correctly" is a little questionable when in next sentence you mention more tappet noise than expected.

While a little loose is preferable than being too tight, Donny is right, when adjusted "correctly" the F134 should sound like a sewing machine.

Do you have a service manual? If not, you need to get one.

Here is the method I use for valve adjustment, for either the F-134 or L-134. I call it my 12 step program.

1) Remove all spark plugs, disconnect the battery, and place transmission in neutral.


2) Mark the #1 position on the distributor body with a light colored Sharpie or chalk.


3) Rotate the engine clockwise with a socket wrench until the rotor is pointing at the mark, easier if you have a helper to watch this while you turn the crank. The distributor rotor will turn counter clockwise. When the rotor is pointed to the #1 firing position it is a few degrees BTDC but both valves will be closed.


4) Make a mark parallel to the ground on the passenger side of the crankshaft pulley.


5) Adjust the valves for #1


6) Rotate the engine 180 degrees until the mark made in step 4 is parallel to the ground on the driver side


7) Adjust the valves for #3


8) Rotate the engine 180 degrees until the mark is parallel to the ground on the passenger side


9) Adjust the valves for #4


10) Rotate the engine 180 degrees until the mark is parallel to the ground on the driver side


11) Adjust the valves for #2


12) Done. Replace the tappet cover, spark plugs, cap and wires then start the engine.

 

Nope. I just pulled on the nut a bit too hard and it snapped

 

Whoa I hadn’t heard of that method!!!
I’ll bookmark this post so I can use it next time!

This is way I did it this time….


there’s a second vid from the same guy for the exhaust valves.

As far as the new tappet noise goes…. It’s mostly because I’ve only had the jeep since December. And this is my first valve adjustment. And they were so tight before they didn’t make a tap at all haha. I googled a couple other vids of healthy f134’s running and it sounds similar to those now.