Tickety Tickety tick

[dhirocz]

You can see that the new design is supposed to have a channel that carries oil around the hollow roller axle, down towards the cam lobe:


as you can see in the photo, this was the rocker from the offending lobe, and it uses the same part number rocker body as the old style, yet has a wider roller and a hollow axle. This is the rocker with the axle and roller removed:


There was no way this lobe would have gotten a constant supply of oil. It killed my 200k mile cam. At 880k miles, it makes no sense to even do a cam at this point without just inframing it and being done, so I guess I'm on the clock. At least I caught it somewhat early.

Maybe I'm wrong, but this is what I am seeing. So maybe this will be something for people to look out for so they dont have my luck. It looks like that lobe lasted as long as it did simply on occasional and splash lubrication only. Kind of amazing, really, but it makes sense why it failed. It was hot as hell and I idled the truck for AC for hours while on my 10 waiting to unload. I havent had to do that much at all since the cam was replaced. When I was driving, it was at least able to get some oil. It didnt get any when I was idling.

[Mattman]

Man that really bites. Hopefully Cummins will step up, but they will probably say something about being over 12 months ago so sorry nothing we can do.

[Rawze]

thanks for sharing this ... makes me wonder how many ppl might have this same issue.

[dhirocz]

Well, they automatically turned down a chance to see the photos after trying like hell to defend themselves, like it wasn't possible that they didn't drill the lube passages. Even though this isn't necessarily under warranty anymore, it did cause damage due to a defective part, and I do think it's understandable. I'm sure they will stick to that, and at best, offer me a new rocker arm; I doubt they will offer me a camshaft, even though their parts guarantee states that they would cover this. That or somehow it'll be my fault because they didn't do the work, or tell me I have to bring it to them, then deny me when I tell them no because I don't want them to end up blaming me then leaving me with a bill to tell me something I already knew (it needs a rocker and a cam). In other words, I have a bottle of lube next to the phone, preparing for their next phone call.

Fortunately for me, the flaking and brinnelling on the cam lobe was rather minor, and I was able to flatten out the damage to the lobe with a few careful strokes of a fine file. I'm hoping flattening the lobe bought me a little more time before it starts to flake again.

I did happen to have a NOS rocker arm in my parts stash so that's going on too.

It wont be together too much longer either, I'm approaching .020 on more than one cylinder as far as exhaust detent clearance goes.

I just want to make it through the summer before I tear it down. Now I need to order a new camshaft to add to my parts before its go time.

[dhirocz]

I found another. Fortunately, this one was near the back of the head so it had oil thanks to the tilt of the engine:
   
I had a new one, stamped 4/16, the was the old style. This one was stamped 9/16, had the same hollow axle with no drilling.
Does someone have a bad old style rocker lying around they can disassemble to verify that it has an oil passage? It's certainly looking like a batch of these 'bad' rockers may have gotten out, and if that's the case, it wouldn't surprise me if Cummins would want to turn a blind eye to it.

It looks to me that these were the exact two I had replaced last time I did a cam. I still have the old valve cam so I'm going to go verify this.