Rocker Arm Question

[Propflux01]

I have a nasty clack going on in the 2100-2700 RPM range. It has been there for the last 15-20k or so, and progressively getting louder. I think I have narrowed the issue to some sort of wear in the rockers, shaft, or holder. I thought about measuring for shims, but the more I read about shims, the more I read about worn shafts. Now if the shafts themselves are causing this, wouldn't it be wise to assume that the rocker arm bushing itself would wear out before the shaft would, since it's a bronze type of bushing? Or do these parts wear rather evenly. Should just say screw it and change out both the rockers and the shafts? I have smith brothers pushrods and stock tubes, and no signs of rubbing. I also have rocker lockers installed, and another set ready just in case. Any suggestions? Please, no "turn the radio up", "use earplugs", etc, as I'm really trying to find a reason for this. Wife has a 2015 switchback which is actually very quiet in the valve train dept. No clack at any RPM on that bike. Thanx in advance

[turboprop]

Have you considered simply removing the rocker covers, pulling the rockers with their supports and inspecting them?

[tdrglide]

Are you sure it's not a lifter.

[Propflux01]

Have you considered simply removing the rocker covers, pulling the rockers with their supports and inspecting them?

Yes, I was trying to see if there was a pattern that Was usually the culprit before I went in. I have shims already I can use. But my question was if I find the rockers bad, would it (Usually) be the shaft, the rocker bushings, or both.

[Propflux01]

Are you sure it's not a lifter.

Yes, it's definitely coming from the top end. Currently have S&S premium lifters installed.

[les]

If you're going to change out the rocker arms and rocker arm shafts, also change out the rocker support bracket. 

[rigidthumper]

Quick check is to swap intake and exhaust shafts- this puts the wear side 180° from current position, and should reveal any excessive shaft/bushing wear.

[tdrglide]

I would avoid shims. Band-aid at best. If you think you need them, something else is worn.
If replacing rocker arms, replace shafts. They are cheap enough.

[chaos901]

Good idea about swapping the shafts as a test, I need to remember that one should the occasion arise.

[kd]

Is this a twin cam?

[Wood]

Not to hi-jack the post... but, Who rebuilds rocker arms, and then hones them to fit on a new shaft for Twin Cams?

I simply don't have the tools to do this job myself.

[Propflux01]

So you swap the shafts, button it up and ride? Or will it show itself another way?

Yes, sorry, its a 103 twin cam.

[tdrglide]

Yes, you can, but inspect first. Might be something obvious. Service wear limits are in the FSM. 

[les]

Not to hi-jack the post... but, Who rebuilds rocker arms, and then hones them to fit on a new shaft for Twin Cams?

I simply don't have the tools to do this job myself.

I do.

[Propflux01]

Yes, you can, but inspect first. Might be something obvious. Service wear limits are in the FSM. 

I have the FSM.

[tdrglide]

Was not trying to offend. Let us know what you find

[Propflux01]

None taken. I am hoping to crack into it this weekend.

[Hillside Motorcycle]

A lifter that is acting up, can make someone suspect that the culprit is in the rocker cover.
What you are hearing when that occurs is lash between the pushrod, and rocker arm cup, inside an aluminum echo chamber.
Another mis-diagnosed valvetrain noise can stem from the use of roller tip rocker arms, on occasion.

[Propflux01]

A lifter that is acting up, can make someone suspect that the culprit is in the rocker cover.
What you are hearing when that occurs is lash between the pushrod, and rocker arm cup, inside an aluminum echo chamber.
Another mis-diagnosed valvetrain noise can stem from the use of roller tip rocker arms, on occasion.

If that were the case, wouldn't it be noisy at all RPM's?

No rollers on this. All stock except for the pushrods.

[chaos901]

All stock except for the pushrods.

Curious what the reason was to change the pushrods?

[Propflux01]

All stock except for the pushrods.

Curious what the reason was to change the pushrods?

They were .20 longer because the base of the Andrews 48's were .20 smaller. In the big picture it prolly would not have mattered, but I wanted to keep it as close to stock geometry as I could.

[kd]

There are plenty of .030 over one piece 120R pushrods out there (or new if need be).

[Propflux01]

At the time Since I was upgrading from 96" to 103", I figured I would go ahead and use a one piece rod instead of adjustables, since I had everything off anyhow.

[Propflux01]

Tore down the rocker covers and assembly. Side play measured at .017 and .018 Within limits, I know, but closer to .025 than .003. I found no evidence of rubbing on the pushrod tubes, removed all 4 pushrods to make sure. Pics included here:

[attach=0,msg1363313]  [attach=1,msg1363313]

[Propflux01]

You can see the wear marks on the rocker arm in the previous post, and see the shaft in this one. Recommendations? Shims? New Arms? Shafts? Leave alone?  ( Note: Rocker Lockers were installed)

[attach=0,msg1363315] 

[attach=1,msg1363315]