Slack in new rockers?

[iamdub]

I just received 16 new "GM Genuine" valve rockers, part number 12681275. They appear to be genuine as well as the bags they're in. As with more and more "domestic" brand parts, these are made in China.

The trunnions have a lot of slack. I know they're supposed to move side-to-side. But these move up and down, too. I don't recall stock rockers having play in this direction.

Vid:

What y'all think? Is someone peddling a load of defects that should've been scrapped?

 

[Foggy]

Crap.. I literally just did my trunnion upgrade on friday night... SO all my rockers
were out on the bench.. I didn't even check or feel them for that motion.. So I'm no
help, maybe someone else can check one they have lying around

 

[Rocket Man]

I just received 16 new "GM Genuine" valve rockers, part number 12681275. They appear to be genuine as well as the bags they're in. As with more and more "domestic" brand parts, these are made in China.

The trunnions have a lot of slack. I know they're supposed to move side-to-side. But these move up and down, too. I don't recall stock rockers having play in this direction.

Vid:

What y'all think? Is someone peddling a load of defects that should've been scrapped?

I did a trunion upgrade on stock rockers on 2 trucks and I can say that’s not normal. Mine didn’t move side-to-side but a tiny bit depending on how far I pressed the bearing in ( too much and it will feel like it’s binding and won’t freely move) and not at all up and down. Why not do a trunion upgrade?

 

[randeez]

Oil gap

 

[gooffeyguy]

I agree with randeez, plus once bolted down the spring pressure will keep movement minimal.

 

[Geotrash]

Mine had a little bit of both vertical and side play in them after 110K when I did the trunnion upgrade on my 2012 last year. I used the BTR kit and they're snug.

 

[Rocket Man]

I guess I never checked mine until after I did a trunion upgrade so maybe that’s normal for stock ones idk.

 

[iamdub]

I did a trunion upgrade on stock rockers on 2 trucks and I can say that’s not normal. Mine didn’t move side-to-side but a tiny bit depending on how far I pressed the bearing in ( too much and it will feel like it’s binding and won’t freely move) and not at all up and down. Why not do a trunion upgrade?

The only upgrade I consider a true upgrade is the Max Effort kit from RPMSpeed. The bearing kits that use the trunnion as the inner race might be (and probably are) better than when they first came out. But, they rely on proper hardening of the trunnion and that's an extra possibility for failure. The Comps failed at this step when they first came out. I'm not totally sold on the brass bushing style for longevity yet, either. My setup isn't any more wild than a stock LS6 and those go for hundreds of thousands of miles on the stock rockers. I'm still using my stock 215K-mile rockers. The aftermarket stuff could be an upgrade, but which brand? How do I know the big name brand (BTR, TSP, etc. isn't a re-packaged ebay brand, all from the same source? I'll never know until thousands of miles later (years for me) if their hardening process was properly performed or if the brass (soft metal) actually doesn't wear like one would think, etc. I just don't wanna find out the hard way.


I moved my originals radially to check for slack and there was no movement. Otherwise, I wouldn't have reused them. That's why these surprised me.

 

[iamdub]

Oil gap

You serious or guessing?

I agree with randeez, plus once bolted down the spring pressure will keep movement minimal.

Yes, between the spring pressure and pressurized lifters, they'd be firm with the gap at the top.


I stopped at a dealership yesterday and compared mine to the previous part number that this replaced (10214664). Other than having different slightly different casting shapes and stamps and not saying "MADE IN CHINA (MAINLAND)" on the bag, they were identical:






After seeing this, I'm assuming it's in the design. But, why? And why does it seem to not be mentioned anywhere else? Maybe it allows the bearings to rotate, distributing the wear more evenly? I don't see why this was even a concern as mine have gone over 200K and still have no slack. Surely the oil between the bearings and trunnions isn't making them that firm.

 

[randeez]

You serious or guessing?

i was mostly not being serious
but theyll prob be fine, tightened down the trunnion is fixed theres plenty of needle bearings in there to support it