Did an engine build earlier this year with brand new ford pushrods. Didn’t bother measuring runout when I put them in because they were brand new. Engine seized 2k miles later unrelated. After that I measure all the basically new pushrods and found 10 of them out of spec by runout. Max 0.010” runout.

I ordered 10 new pushrods from the local dealer, and the first one I measured it out at about 0.012” runout. A brand new pushrod.

Why the heck does ford think it’s wise to package a long slender part with runout spec in a plastic bag that can be easily mishandled and bent.

Would you guys fight for a return to the dealer and trying to play lottery again to see if the next batch comes in straight? I have a feeling my original rods actually came out of spec like this too but I can’t prove it, especially with such significant engine damage.

I also have a set of enginetech pushrods that I ordered from rockauto that I was thinking of using but changed my mind last minute. I was planning on returning them but I’m considering breaking the seal and measuring those. I wonder what’s more important: reputable source, or in spec runout.

 

Pushrod runout depends on the engine. As long as the wall and diameter are sufficient for anything except a hard fault, the straightness does not have to be perfect, despite what the DIY world says. (I've got a clue; I was the first person in the country to build carbon fiber pushrods with the company I initially worked for). Secondarily, pushrods should be sized like a fuse - to bend when there is a hard fault.

International's spec for the pushrods, where Ford still may be sourcing them, is a maximum of 0.010".





As my wife says, I don't throw out nuttin.





Rather than digging out v-blocks wherever they might be, I knocked together what does work with some hot glue.










So these are my used set, 12 left after I cut others apart to make adjustable pushrods so I could check piston to valve clearance—2010 vintage. I'd prefer it to be under 0.006"; anything over the book spec I'd certainly send back. Considering where we are today, it would be interesting to know where they were made based on the packaging, if it says on the package.

 

I'd have never thought about a glue gun for building a fixture, thats genius!

 

No need to complicate your life. It's quick to make, quick to knock down. Roll the pushrod at the ends with your fingers, but it takes a feel. Easy to put the pushrods in, too.

 

I finished measuring all 10 new ones, 8 were out of spec as high as 0.018”. The two that were in spec: 0.006 and 0.008. One or two were also right at 0.010.

I’ll be taking them to the dealer for their response. They had to order them so most likely wait another few days to get more in.

I have half a mind to take some old pushrods and test out bending them back in straight. It’s obvious in the fixture which side is high.

Or maybe I shouldn’t have my fixture v-blocking in the ball tips? Maybe I try again with the fixture holding the shaft instead.

 

That's disturbing that they are that out of spec. Do you see that on a glass plate?

 

Looking at your fixture, are you measuring off the ball or just slightly behind the ball? It may not matter, and it should not influence the values this much, but the ideal is off the ball and, if not, a little way from the weld. You can have some tube distortion from the welding process. These can be spin-welded, so the pressure during the process along with the heat can make this area a little wonky.

 

Absolutely, they wobble if you roll it across the table. I don't have glass to try but my work bench still produces that behavior.

For the fixture, the way I had it designed, the ball was the interface to the V-block in the fixture. I updated the design and re-printed so that it interfaces to the shaft instead. Unfortunately really not much different. I measured two of them so far and both were about the same.

Referencing the international manual though, they suggest rolling the pushrod on a flat surface to check straightness. In this method the ball would be the controlling feature.

Erg, just frustrating

 

I took out the enginetech pushrods, they certainly appear to be of lower quality. Feel lighter, and the discoloration from welding the ***** is significantly larger. Probably both due to thinner tubing used. But at least they measure in spec. Still don't want to run them though.

Another angle I thought of was that I noticed the ford pushrods appear to be seamed tubing. I took my micrometer and measured every 22.5deg (or so) along the circumference of the rod. I found the circumference is certainly not a circle. Runout is a function of circularity and axial concentricity. My measurements show from the largest diameter to the smallest diameter is about 0.006" which again is only half the story. But still 0.006" circularity is quite a bit when the spec for runout is 0.010".

Once again I find myself asking if I'm looking too close, how many mechanics doing head gasket jobs actually measure their pushrods before putting them in.


The chart below shows the diameter measurements, note that only indicated here is circularity, not concentricity. This is only half of the runout function. The true center is almost certainly not where the chart indicates.

 

Alright so to close out this story:

Like I said, I bought 10 from the dealer and 8 of them were 0.010"+. I brought the 8 to the dealer parts counter with my runout fixture, parts guy goes back and asks his mechanic to come out and look. Mechanic steps up to the counter and says the spec is 0.010" or 0.015" but didn't know for sure. (I know because I have that ford service manual .pdf) He looked at the rod I was showing which was 0.018 out and said "yeah that one is definitely bad". Okay, cool so parts guy had me fill out a form to warranty replace all 8 rods and I got a new set of 8. Took them home and measured and one of them was 0.014", two were at 0.010". I decided to let the 0.010" fly but I took the 0.014" back to the dealer. I had to go back and forth with their manager a few times:

"we've sold hundreds of these and no one has ever returned for this problem"
"we haven't heard any engines failing from the hundreds of rods we've sold"
"our mechanic said 0.010" to 0.015""

Back and forth: "is this a new part, yes, does it meet spec, no, then how is this not a warranty problem"

Ultimately they grabbed a handful of rods off the shelf and let me measure until I found one I liked. They asked me to not mutilate the bags i.e. they're going to sell them to someone else. Honestly the dealer was crappy, its not their fault the rods were bad, but they should be fighting with Ford, not me.

Anyways, all said and done. Likely some out of spec rods everywhere.

 

That's sad to read.

Here is a quick video of how pushrod manufacturers straighten pushrods before they get boxed. Or should be.


And a picture of how Manton does it when making racing pushrods.




It can be done at home if someone is hyper. They are not hardened steel.