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> push rod wear, can anyone explain?
malcolm2
post Apr 5 2014, 07:24 PM
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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?

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stugray
post Apr 5 2014, 07:41 PM
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wow that was close to failure!

the pushrod retainer spring was installed wrong and it has been rubbing.
Apparently for a long time.
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r_towle
post Apr 5 2014, 07:41 PM
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Push rod tube retainer spring is installed improperly and rubbed against the push rod....for a while it looks like.
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malcolm2
post Apr 5 2014, 07:59 PM
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QUOTE(r_towle @ Apr 5 2014, 08:41 PM) *

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



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.
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stugray
post Apr 5 2014, 10:29 PM
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maybe that's someone's idea of lightening the valve train (IMG:style_emoticons/default/confused24.gif)
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Bob L.
post Apr 5 2014, 10:52 PM
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Maybe the DAPO flipped them around when they noticed it? (IMG:style_emoticons/default/confused24.gif)
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Black22
post Apr 5 2014, 10:59 PM
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That actually looks machined! Almost too perfect for rubbing on the retaining wire.
(IMG:style_emoticons/default/WTF.gif) (IMG:style_emoticons/default/confused24.gif)
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VaccaRabite
post Apr 6 2014, 09:23 AM
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QUOTE(Black22 @ Apr 5 2014, 11:59 PM) *

That actually looks machined! Almost too perfect for rubbing on the retaining wire.
(IMG:style_emoticons/default/WTF.gif) (IMG:style_emoticons/default/confused24.gif)

(IMG:style_emoticons/default/agree.gif)
That looks like it was turned on a lathe. And it's not on the spring end.
Zach
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VaccaRabite
post Apr 6 2014, 09:48 AM
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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!
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McMark
post Apr 6 2014, 09:49 AM
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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.
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Jake Raby
post Apr 6 2014, 09:49 AM
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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.
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MrHyde
post Apr 6 2014, 10:51 AM
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That looks like one "spirited drive" away from becoming 2 pieces
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stugray
post Apr 6 2014, 10:55 AM
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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 (IMG:style_emoticons/default/biggrin.gif)
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Jake Raby
post Apr 6 2014, 01:04 PM
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QUOTE(stugray @ Apr 6 2014, 08:55 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 (IMG:style_emoticons/default/biggrin.gif)


Just because it lives doesn't mean that it won't deflect.. Deflection costs lift and duration at the valve.
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veekry9
post Apr 6 2014, 02:11 PM
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Turned on a lathe with a TNMG insert.

Attached Image

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//
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McMark
post Apr 6 2014, 05:05 PM
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QUOTE(veekry9 @ Apr 6 2014, 01:11 PM) *

Turned on a lathe with a TNMG insert.

Teenage Ninja Mutant Gecko?


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Elliot Cannon
post Apr 6 2014, 07:15 PM
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Push rod tube retainer springs? (IMG:style_emoticons/default/confused24.gif) I'm not sure what you're talking about. (IMG:style_emoticons/default/av-943.gif)


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Black22
post Apr 6 2014, 08:14 PM
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(IMG:style_emoticons/default/slap.gif)
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Jake Raby
post Apr 6 2014, 09:52 PM
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Dual springs with stock rocker studs.. Playing with fire!
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Elliot Cannon
post Apr 6 2014, 09:59 PM
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Playing with fire for 25,000 miles. So far, so good. (IMG:style_emoticons/default/biggrin.gif)
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