When is it time to replace the rocker assembly?

Duke

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Joined
Aug 28, 2010
Messages
139
Location
San Diego, CA
I recently purchased a rebuilt 2f head from Marks Offroad (super nice guy btw) and wondered if it was also time to replace the rockers.

What do I look for to make that determination?

How do you know if the rocker bushings are worn?

I've got 2 rockers that no matter how much I adjust the valves, they continue to "knock/rattle",

Is this a sign of a weak lifter? Weak valve spring?

Interested in your thoughts and advice. Thanks to all, I really appreciate the knowledge here.

For what it's worth I have dry and wet compression numbers that come in at 150+ on all cylinders. I am using 20-50W Royal Purple oil after an extensive cleansing over the space of 6000 miles. It's much quieter now since the cleaning but still have 2 that make a lot of noise. I can feel that when I hold each one individually. :cheers:
 
Joined
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Messages
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There are two areas to consider when you examine the rocker arms fro wear; the shaft bushings and the arc surface where it engages the valve stem. The noise you are hearing could be coming from the wear on the arc surface. This wear can cause a relief or notch to be worn in this surface and what happens is when you are set the valve lash you are setting it at the high surface and not the surface that is actuating the valve. So the actual clearance can be greater than what you are feeling with the feeler gauge. You can have these ground, but I was not able to find anyone to do this so I used a fine knife sharpening stone and carefully honed the arc down to the level of the wear. Don't get them hot by grinding or the temper will be lost. Good luck.
 

Duke

SILVER Star
Joined
Aug 28, 2010
Messages
139
Location
San Diego, CA
I wondered about that as being the possible cause. I'll look at that more closely when I actually replace the head. Thanks for the info.:)

There are two areas to consider when you examine the rocker arms fro wear; the shaft bushings and the arc surface where it engages the valve stem. The noise you are hearing could be coming from the wear on the arc surface. This wear can cause a relief or notch to be worn in this surface and what happens is when you are set the valve lash you are setting it at the high surface and not the surface that is actuating the valve. So the actual clearance can be greater than what you are feeling with the feeler gauge. You can have these ground, but I was not able to find anyone to do this so I used a fine knife sharpening stone and carefully honed the arc down to the level of the wear. Don't get them hot by grinding or the temper will be lost. Good luck.
 

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