Primary Noise 2010 Road King

Question I’m a Premium member and just came back from a long ride of 1400 miles. Nearing the end of the ride I started hearing primary noise rattling from my 2010 HD Road King. The next day after arriving home I drained the fluid and found not only the metal paste on the magnetic drain plug but several metal shards about 1/2 to 3/4 inch long. I commenced changing the oil but have not ridden it since. I have another ride to the Adirondacks in two weeks so need to get it checked. A new starter clutch & clutch assembly, primary seals, bearings and gaskets were installed last year and I’ve ridden about 12,000 miles on that. No other problems or noises and I’ve always run Amsoil 20W/50. I have 60,000 mile on her. What are some likely things to look for? Dan S



Answer Top breathing engines breath, or vent, through the top breather bol Dan, being that someone has already been inside your drive compartment, it could be a few things. The metal paste is normal wear. Usually from the charging system. Once you pull your outer primary cover, it will probably be obvious. If you did not notice any performance problems on your last ride, it could be as simple as a bolt that has come loose. Let’s hope it’s something silly like that. Please give us an update.



Update: As an update to the “Primary Noise” posts; I was told that a failing compensator damaged the rotor, clutch and starter clutch and all had to be replaced along with the associated gaskets and fresh fluid. I can attest that in riding the bike the 35 miles home the difference in sound and, seemingly, performance are remarkable. Strong, crisp and responsive… just how I remembered her :). Now I’ll be confident as I head to the Adirondacks for some mountain R&R. Dan S


Newsletter and fellow Hogger Feedback:
If this okay, just add a little Technical info to this query, unfortunately this may be a little more sinister than it appears. Here’s for why, I don’t now if you know that the ‘Twin Cam’ motor has an inerrant manufacturing problem with crankshaft run out.The in depth technical reasons I won’t further here.
I have seen on several motors the outcome of this as described, with shards of material being removed from the inner primary cover behind the clutch. This is due to crankshaft run out causing the clutch to oscillate with the described outcome. This also causes primary chain wear the outcome being the rollers break up. There’s always one doom and gloom merchant is’ent there !!!!!!!!
I had cause to remove my Primary cover on my 07 Softail, during this I put a DTI on the crank and measured the run out, I have 4 thou, now to me as a retired Mechanical Engineer, and an engine builder, that’s way out of tolerance, and scrap, I’m going S&S but that’s another story. Now you know why Harley does not gear drive there cams?????? But that’s maybe for another time……..
If it’s okay I would suggest that when the Primary cover is removed on this motor that the crankshaft run out is checked, just in case. Hopefully this motor as not got the above problem.
Thanks, Keith

Our Feedback:
Thank you for the great feedback. Yes, when we did the cam chain tensioner videos we show the measurement and why many will not be able to go to S&S gear drive.


Related Videos:
Harley Compensator Upgrade

Rear Belt Removal

Cam Chain Tensioner Class

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19 Responses to “Primary Noise 2010 Road King”

  1. Fred

    I have a 2012 triglide. Hearing a metal chattering sound after motor is hot while cruising at 3000 rpm. Decillerate or give it gas it goes it goes away. Sounds like it’s coming out of the primary. What could it be. 13,000 miles on bike.

  2. Paul Johnson

    This post got me thinking of my 2013 stock Ultra primary chain. other than the metal on the magnet, When the engine gets turned off the primary would rattle, Starting off from Stop sign, just as clutch Lever is released the primary would Shake and rattle till the Clutch lever was all the way released. I found metal on the Drain plug and the Primary Chain has 1/4" difference the tight spot and the loose spot on a primary Chain. I measured the Crank run out it was good at .002, and the tranny shft is .003, so the runout theory does not apply. The chain spec is 5/8-7/8 cold. On the tight spot it is 5/8 and at the loose spot it is 7/8. I plan on R&R the Compensator, Chain, and Tensioner with SE manual Tensioner. What else could it be? I can't think of anything else it would be.

  3. Jack

    My 96 Fatboy is seems to be making a chirping noise, that sounds like it’s coming from the primary and only under power. Quite when I back of on the throttle?

  4. Kucklehead

    Didnt know that i could measure the runout through primary, though its through the cam side only, good to know.

  5. MICHAEL

    <strong> Ticket 16653 I keep hearing about PRIMARY NOISE, what do I listen for? I have a 2007 Electra Glide Standard, it it getting close to 40k on it, I know what maintenance I need to be doing and checking. I am not sure what to listen for if it was showing any unusual signs of being worn.

  6. Gary

    is there any videos showing how to replace inner primary bearing?

  7. Mohamed Wagdy

    I still dont understand why I'll not be able to go to S&amp;S gear drive on my 2005 FLSTFI TC?

  8. Henry mcguire

    I replaced my clutch 2yrs ago and I put in a Barnett, clucth seems to work fine , no slip. But every once in awhile when engaging at stop light I get a nice like a squeak sound or might even call it a squeal. My bike is a 97 road king. Thanks for any advice where to look.

  9. Richard

    Hi, I seem to be seeing more and more of this issue at my workshop.. Compensator changes are more and more the cause of having to get into the primary.. .. but what really puzzles me is more than often i am finding (deep at times) scruff marks just behind the clutch basket in exactly the size of the starter ring mostly on the side in between the comp and clutch basket clearly indicating that the clutch basket has been put through excess pull towards the compensating sprocket causing the basket to rub against the primary..On closer inspection you will most likely find that the splines on the clutch hub are sheared but only at the very edge nearest to the inner side closest to the inner primary bearing which might be of support to the idea that flex on the main shaft is the result but not the cause here ..the inner primary support bearing and race are also very commonly severely damaged.. What i am not to sure of is what really is the root cause.. Would run-out on the crankshaft cause so much wobble to the clutch basket, enough to the effect that the approx 3/16 clearance between inner primary housing and clutch to be insufficient?.I am not debating here just tying to get to the root..

  10. Gerard

    Hi I have a 2007 cvo road King with 36000 thousand miles,think I amend you about my primary back in January well I've only got my parts now I have this new upgrade compensator + new clutch and starter clutch and pinion but when I took off inner primary cover I seem to have a good play on main drive shaft is this normal because there didn't seem to be any play before I took off clutch?im talking about play up and down or sideways not in and out ? Also I'm a premium member but I can't seem to find any cvo video ? Thanks. Regard Gerard