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Posted by: malcolm2 Apr 5 2014, 07:24 PM

Just helped remove a 1.7 today and this is what came out of it.

There were probably 4 push rods that had varying amounts of this wear. I could make a guess at what caused it, but this end was seated in the lifter.

Just curious.... anyone want to guess?

Posted by: stugray Apr 5 2014, 07:41 PM

wow that was close to failure!

the pushrod retainer spring was installed wrong and it has been rubbing.
Apparently for a long time.

Posted by: r_towle Apr 5 2014, 07:41 PM

Push rod tube retainer spring is installed improperly and rubbed against the push rod....for a while it looks like.

Posted by: malcolm2 Apr 5 2014, 07:59 PM

That is what I thought. But the end with the notch was opposite the end with the spring. All the rods with damage were seated in the lifters. I pulled the 1st one out and said, "man, I wonder what that lifter did to the push rod."

So the next guess is that someone did a tremendous dis-service and installed junk parts.

Posted by: stugray Apr 5 2014, 10:29 PM

maybe that's someone's idea of lightening the valve train

Posted by: Bob L. Apr 5 2014, 10:52 PM

Maybe the DAPO flipped them around when they noticed it?

Posted by: Black22 Apr 5 2014, 10:59 PM

That actually looks machined! Almost too perfect for rubbing on the retaining wire.

Posted by: Vacca Rabite Apr 6 2014, 09:23 AM

That looks like it was turned on a lathe. And it's not on the spring end.
Zach

Posted by: Vacca Rabite Apr 6 2014, 09:48 AM

That was turned on a lathe. Someone goofed on their geometry and started shortening the pushrod. The left cut is the same angle as the shoulder and the groove is the same length as the pushrod tip.
LOL!

Posted by: McMark Apr 6 2014, 09:49 AM

If the lifter is doing its job right, it spins a little each time it moves. So the pushrods turn with it and this is what you get.

Posted by: Jake Raby Apr 6 2014, 09:49 AM

Nope, retaining wire got it.. It was probably inverted at some point by someone who didn't care, or didn't know any better.

The pushrod rotates as it reciprocates, which is what leads to this perfectly machined surface.

Posted by: MrHyde Apr 6 2014, 10:51 AM

That looks like one "spirited drive" away from becoming 2 pieces

Posted by: stugray Apr 6 2014, 10:55 AM

That just makes me wonder how much we could machine off the pushrods and they would be fine.
Every gram we take off the valve train helps

Posted by: Jake Raby Apr 6 2014, 01:04 PM

Just because it lives doesn't mean that it won't deflect.. Deflection costs lift and duration at the valve.

Posted by: veekry9 Apr 6 2014, 02:11 PM

Turned on a lathe with a TNMG insert.



so.. you want to machine.
Titanium Nitride coated by vapour deposition.
tnmg is the code descriptor of one of thousands of configurations available.
the catalogs are great tomes too large to print these days so we download pdfs.
//http://www.sandvik.coromant.com//

Posted by: McMark Apr 6 2014, 05:05 PM

Teenage Ninja Mutant Gecko?



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Posted by: Elliot Cannon Apr 6 2014, 07:15 PM

Push rod tube retainer springs? I'm not sure what you're talking about.


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Posted by: Black22 Apr 6 2014, 08:14 PM

Posted by: Jake Raby Apr 6 2014, 09:52 PM

Dual springs with stock rocker studs.. Playing with fire!

Posted by: Elliot Cannon Apr 6 2014, 09:59 PM

Playing with fire for 25,000 miles. So far, so good.