Hey everyone! I’ve got a ‘64 f100 with a 292 y block. It seems to have dropped a pushrod at the farthest passenger side. I plan to pull the intake and valley cover sometime soon.

Anybody else experience this before? How can I prevent this from happening in the future?

Thanks!

 

I make sure I’m on top of adjusting valve lash regularly, maybe I missed one?

 

It used to be fairly common "back in the day"? I'm not sure what the cause. Sludge or varnish maybe in the valve or valve guides? Bent pushrod.

If you look close, might be able to fish it out with a magnet, it might not have dropped far. I think it was also common to find "extras" upon tear down, too - so it probably won't hurt anything otherwise. I mean, if you weren't really looking forward with enthusiasm to pulling the valley pan.

If the rocker arm face has excessive wear the clearance adjustment is usually inaccurate, when using a flat feeler gauge.

 

Thanks for the advice, I was able to fish half of the pushrod out. I almost had the other half but it fell down. I ran out of free time so I have to work on it some more as soon as I can.

 

If a pushrod is broken that points to another possible problem - check that the intake manifold bolts aren't too long. They can intersect into the pushrod passages. An inspection mirror and strong flashlight will help here. There are also two holes at the rear of the heads, same problem, sometimes peeps plug them with bolts, that are too long.

 

You’re a smart guy! My truck did not have the original plug wires or looms. I bought wire looms and bolts. Turns out if the bolt is too long on the passenger head it can easily make contact with the pushrod closest to the firewall. I had no idea making contact was even a possibility. I just happened to see the bolt down in the pushrod hole so that will definitely be getting replaced with a shorter bolt.

Thanks again!

 

Good info for a y-block.

Y

 

Yeah ... I'm not so smart, so my preference is to learn from other people's mistakes. Learned this "feature" the hard way on my own. Bolted up an open hole on the back of the driver side head some years ago. It wasn't too long before it started running very poorly ...

 

With a little patience and redneck ingenuity I was able to fish the pieces of pushrod out.

Any tips on how to install the new one? I’ve got a service manual I should probably look through first.

 

It's pretty simple, roll the engine over till that particular piston in the cylinder is at TDC, either compression or exhaust shouldn't really matter I don't believe. The idea here though, is that the lifter is resting on the heel of the camshaft lobe.

Make sure the ball end of the pushrod is correctly seated directly in the cup of the lifter. Then tighten the ball adjuster on the rocker and set the valve lash to .020" cold. If there is a lot of wear on the face of the rocker arm tip it can be difficult or impossible to obtain accurate clearance as a flat feeler gauge will tend to bridge across the wear pockets and give a false indication.

I have had good luck using the "Walt Nuckels" method of Y-Block valve lash adjustment. From a zero lash point, taking up the clearance, the pushrod will just spin freely with oily fingers. From zero lash, loosen the jamnut exactly 1/4 turn. This turns out to be very close to .019" due to the thread pitch of the ball adjuster, it is kind of like a micrometer in that way. This method of adjustment also takes into account for any excessive wear or slop in the rest of the valve train, so the end result it is a more precise adjustment than using a feeler gauge. Convenient and fast, no special tools required.

 

Thanks for the information! I hope to have everything put back together in the next day or two.

 

You will need to remove the shaft assembly to get enough room to install the very end pushrod. The piston should be at tdc on compression. Farthest passenger side is the #4 cylinder. #4 is the third in the firing order sequence. Before you remove the shaft, turn #1 to tdc on compression (both valves will be closed and therefore the rockers will be "loose") Then turn 180 degrees and that should put #4 in the ball park of tdc on compression.

Check the fit of the pushrod cup against the adjuster ball, before you install the pushrod.

 

Thanks to everyone for all the help! I installed the new pushrod and fired it up. Everything seems to be running smooth again! Time to shorten that bolt and we should be good to go.

 

Good deal, thanks for the update