For all of those older truck owners (the trucks' age, not yours), the rocker
arms aren't universal. If you keep a spare rocker in the glove, I believe
you will need to keep four different ones to keep yourself covered in case
you break one. & also to Jerry, was your rocker arm shaft receiving
49 3104 216 5-window
----- Original Message -----
Sent: Tuesday, May 02, 2000 9:00 PM
Subject: [oletrucks] broken stamped Chevy V-8 rocker arm...causes?
> Ok, somewhat off-year ( 1974 Chevy 3/4 ton truck ), but applicable to
> vehicles....my truck has had the valves tapping for some time ( had the
> rebuilt 2-3 years ago, some 30k miles on it ), and coming back from a road
> trip, it started running extremely rough. Drove another hour with it like
> this and got it home ok, then it sat for 10 days before I could get to it.
> Pulled the valve covers off, (because we had heard the rockers tapping at
> mph, so I knew that they needed "some" adjustment...) and found a rocker
> had cracked in half, on the # 5 cylinder. Rockers were extremely loose on
> and #6 cylinders as well. I bought a replacement, did rough adjustments to
> take the major play out of all the extremely loose ones, then put it all
> together...bingo, runs great, better than before the "accident". Now, my
> worry...I didn't readjust the valves after the initial adjustments right
> after the rebuild, and it's been like that for 2-3 years. Would those
> rockers also have received enough stress to start them to crack as well?
> Should I be concerned about them? I"ve had many Chevies for years, ( '57,
> '64, '66, '71, '73, etc ) and never seen a cracked rocker arm. The truck
> 125k miles on it total, so are those arms due for replacement? I bought a
> spare rocker arm to keep in the glovebox, in case it decides to break
> one. Just wanted to know what some list members think about this.
> Also, running the engine with a valve closed constantly, what might be
> consequences of that? I think it was the 6th valve, don't know whether
> intake or exhaust side, but it might have been working some before the
> totally sheared in half. My dad's Chevy truck had lost a pushrod before,
> it bucked something fierce after that, my truck just ran rough. maybe a
> sticking valve, and the new rocker might start doing the same thing? just
> hoping for the best right now! I'm gonna drive it short distances for
> and see how it does. Thanks for any input, Oletruckers....
> Jerry Casper
> '74 Chebbie running again, but worried about it...
> 55 Suburban
> oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959
oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959