Author Topic: Rattle from primary  (Read 684 times)

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Offline JW113

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Rattle from primary
« on: March 09, 2017, 06:24:17 PM »
The weather out here has been fantastic, so been riding the Ironhead to work. However, it's developed a strange rattle from the primary that comes and goes. Does not happen at a stand still, in neutral, and varying the rpms quickly or slowly through the range. But in gear, any gear it seems, it will do it intermittently, seems like in the 2500 to 4000 range. And seems to be related to load, as in maybe just barely under load, not heavy throttle load and accelerating. More like at a steady speed or very very light acceleration. And maybe even under very slight de-acceleration?

I'm thinking maybe some strange oscillation between the chain and adjuster, since under load the bottom thread of the chain is slack.

Anybody else experience this?

thanks,
JW
2004 FLHRS   1977 FLH Shovelhead  1992 FLSTC
1945 Indian Chief   1978 XL Bobber

Offline Hossamania

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Re: Rattle from primary
« Reply #1 on: March 11, 2017, 10:47:16 AM »
Have you checked both chains? And checked your sprockets for excessive wear?
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Offline JW113

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Re: Rattle from primary
« Reply #2 on: March 12, 2017, 10:24:55 AM »
Gonna pop the plug and check the primary chain today. I just had it apart fixing an issue with dragging clutch (due to cursed 'red' spring) a couple months ago, the primary sprockets and chain "looked" OK but who knows. Not sure I even know how to tell a worn out primary chain, never replaced one before. Even with close to 200K on one bike. The rear chain and trans sprocket are brand new, just re-geared it with a 23T sprocket. The rear 51T looks good, no cupping. Will check the adjustment again.

I don't think that I've ever had a clutch hub bearing go bad, so no idea what sort of sounds/symptoms that would have. It's just kind of odd how it will be quiet as can be, then suddenly sounds like it's gonna fly apart. Then goes quiet again. Weird.

-JW
2004 FLHRS   1977 FLH Shovelhead  1992 FLSTC
1945 Indian Chief   1978 XL Bobber

Offline Scott P

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Re: Rattle from primary
« Reply #3 on: March 16, 2017, 05:52:24 AM »
Chain probably swatting the cases, or better yet, it's fubared the adj, from being too loose........would be my first guess.
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Offline Burnout

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Re: Rattle from primary
« Reply #4 on: March 17, 2017, 07:12:30 AM »
If it's making big noises do not start it again.

Pull the primary cover and inspect, the adjuster probably came apart or just loose.
They don't call me Ironhead Rick just because I'm "hard headed"

Offline JW113

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Re: Rattle from primary
« Reply #5 on: March 18, 2017, 11:06:04 AM »
I think I found the culprit. The spring is broken. Just ordered a new adjuster kit for the 1979 and later with formed wire spring. Hopefully that cures it.

-JW
2004 FLHRS   1977 FLH Shovelhead  1992 FLSTC
1945 Indian Chief   1978 XL Bobber