Thread: Broken push rod blues

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re: "the more i learn the less i know"
Hi boys 'n girls,
I had a broken push rod... (snip to present day
All rods and rocker assemblies have been replaced. I have all new lifters. I didn't soak lifters or pre-oil them, but used plenty of assembly lube on both ends.
(Comp Cam matched lifters, but did not replace cam. Also, did not replace timing chain, etc. Heads were inspected and new valve guides installed, etc.).

Followed basic rocker adjustment procedures: TDC, tighten #1 until rod "drags", then 1/2 turn more. While in this position, adjusted #2,5&7 int and 3,4&8 exh.
Then turned 360 and adjusted #3,4,6&8 int and #2,5,6&7 exh.
Started engine (woohoo) but had some clatter, so tried to adjust it out with engine running. (I have read earlier posts in this forum from Denny W, techinspector, dave s and others, but now I'm really confused.)
The #5 exh rocker seems really loose and will not tighten with engine running.
I have adjusted this thing repeatedly... walked away a half dozen times to keep from blowing it up... very frustrating... been at it for a week and need advice (or a shrink!)
(I'm much too old for this kind of stress!!!!!) LOL

I'm assuming these are hydraulic lifters. Sounds like that lifter collapsed.

Thanks guys,
Denny... straighten me out here, ok? After I set TDC with the timing mark at 0*, what exactly do I turn 180*? Do I simply turn the crank 1/2 revolution, putting the timing mark on the opposite side?

ok... thanks again... will get off my butt and go out and try it one more time this morning.

Originally posted by run_gmc
ok... thanks again... will get off my butt and go out and try it one more time this morning.

oh, yeah... will try it with engine running, too... but need to find out why #5 wouldn't stay tight...
later... have a great day

OK... it runs... but a little rough.
I've checked, rechecked... adjusted and re-adjusted.... still running rough at low idle and doesn't seem to have the power it had before I tore it down. What am i missing here?

Denny... you are da man!
I figure it this way: I'll check first for correct firing order, then for vacuum leaks around the intake and throttle body, then check for other vacuum leaks. If all is well, I'll reset the timing (i'm figuring that 12* btdc is where i had it set before the push rod problem... it ran great, btw). If necessary, I'll pull the valve covers and re-adjust using your procedures for adjusting them with engine running. Currently no clatter, but if they're not really tight enough, (or too tight) there would be rough running, right?
Does this sound like a good way to go? Too much? Too little?
Thanks again...
btw... Do you know where Marengo is?

Denny... my first job after high school was in Marengo... that was in ... ah... 1966 and that's a long story...
Now... back to the engine: I followed your procedure and did the adjustment with the engine running. Made a HUGE difference.
Set the timing to about 14* before tdc and she is developing power like before the rod broke.

New problem: Will not idle with A/C on and engine at running temp. After it dies, it is really hard to start.. like it has a hard time turning over. After a brief cooldown it starts and runs fine as long as A/C stays off. I can "feather" the gas pedal and keep it running. Any ideas?

Engine temp normal, 195*T-stat. Same as always.
Backed timing off to 10* before tdc.
Checked plug wires and distributor, cap, rotor. All ok.
Regapped plugs... OOPS>>> Rookie mistake discovered.
Found the #7 plug cracked around the base of insulator.
Put in a new plug and now she's as smooth as a baby's behind and almost as powerful! Great advice from all you guys... Thanks a million! Owe ya one, Denny. The process has taught me a lot.