Check Your Rockers!

My truck had the same scoring at 240K miles. The little oil galleys that feed the rockers had a little bit of soot buildup but not enough to block flow, just hinder lube flow a little.

With all the trucks having this issue, is it really a problem? Who has had a rocker seize up and cause valve contact?

I'm not so sure this is a problem per say, just a high wear location that looks bad but doesn't really affect anything.
 
At 56k miles, I had significant galling and pitting as well. Number 3 exhaust rocker was so bad that I couldn't rotate the trunion inside the rocker by hand.

I kindof wonder if dry start up is significant cause for wear. With a manual oil pressure gauge, sometimes it can be 20 seconds or longer before oil pressure starts to come up.

If you trace the oil feed path, the rocker trunions are about the last place that gets oil...and the paths are split a bazillion times or so up through each pedestal, across a groove, circumferentially around the bolt holes, through a little diagonal hole, around an annular ring, through another diagonal bore, out to the crosshead or pushrod head.

One reason I say this, is because I had very little wear on the trunion and rocker surface where the annular oil ring is; rather, all the galling occurred inboard of the ring, where there is no direct oil path.

Are there any roller rocker options that are designed for daily drivers and less than $2k?

I know DonM was experimenting with a wear-resistant low friction coating on the trunions/rockers, but I haven't heard much about this lately.

--Eric
 
SWALLDOG said:
Forgive My Ignorance But What Is Zddp?
Click to expand...

It is a zinc/ phos. additive that is the additive oil manufacturers use as their EP (extreme pressure), anti wear additive package. The government has stepped in and forced the oil companies to reduce this necessary EP additive as it supposedly clogs cats. It must be used. Also this additive gives itself up over time. So it needs to be replenished or replaced with oil fills. Several companies make this product. I find it locally from Lucas Oil as a break in oil additive known as Zinc+.
 
IMO, It's not a performance wear issue, it's a galling issue derived from debris getting caught between the rocker and the pin, the rocker is softer than the pin, so naturally it will wear the most, cummins spec only gives about a 2 thou clearance anyway.

Debris thats causing this is mostly from ingested dirt from the oil filler cap being opened and filter replacements. Another cause that is suspect, is break in metals, as i have seen these destroyed rockers in trucks with less than 20k on them.
 
03kbcobra said:
It is a zinc/ phos. additive that is the additive oil manufacturers use as their EP (extreme pressure), anti wear additive package. The government has stepped in and forced the oil companies to reduce this necessary EP additive as it supposedly clogs cats. It must be used. Also this additive gives itself up over time. So it needs to be replenished or replaced with oil fills. Several companies make this product. I find it locally from Lucas Oil as a break in oil additive known as Zinc+.
Click to expand...
I read some where some one ran some test on differant oils and additives to see how much zinc was presant. It was found it's best to use CI-4+ oil. The best grades of CI-4+ with a 12tbn allready have over 1400ppm zinc. The CJ oils have very low zddp and adding a bottle of zddp additive only raised the zinc by 100ppm. Not much.
Billy
 
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