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clunk?

8K views 30 replies 12 participants last post by  palmpalm 
#1 ·
Say I'm in 6th gear at 2000 rpm cruising along in my 2012 FLTRX. If I roll off or on the throttle there is a clunk from below me. I never noticed it before. bike has about 15000 miles on her now. It's weird, like there is some clunky engagement of something. If I pull the clutch lever in and roll off and on the throttle the clunk goes away. What is this???
 
#5 ·
It sounds like you may be "lugging" the engine in that gear at 2k rpm. To me that's a very low rpms to run. Try getting it to make the "clunking" noise at a higher rpms in that same gear.
 
#6 ·
Did it multiples times. No change. And it's not gear or Rpm specific. It happens in every gear at every rpm. Just can't hear it so well unless around 2000 rpm because of engine noise. Has nothing to do with lugging the engine.

Harley tech rode it and says it's fine but I suspect he never heard the noise.
 
#8 ·
My 13 seems to do this as well. I was thinking clutch adjustment but haven't checked it yet. I only noticed it recently with about 17500 on the clock. I'll have to wait to get her back to figure it out. It's in a crate on its way to the pacific for a boat ride to HI. I miss it already...
 
#10 ·
I saw an independent Harley mechanic and I told him about the clunk; he went over to my bike and turned her on, put her in first gear and let the clutch in and out fast and it made the exact same clunking noise! He told me it must be the compensator sprocket. He says he knows that as of 2011 they were updated to the SE compensator on all regular FLTRXs but he says he has seen this before as well even with the SE compensators. He said that on a few he has put in the part made for the Trike system because it's a bit more heavy duty.
 
#11 ·
They since updated the SE compensator again.
 
#13 ·
Since when is 2k lugging the engine??

I get this same clunk/clank.
I can get the same thing to happen rolling OFF the throttle as rolling on. You don't have to do it hard to hear it either. Rolling off, it sometimes sounds like it 'bounces'. HD, as expected, said, "sounds normal for the compensator." Whether I believe that or not.
 
#18 ·
I'd stay stock with the stock flywheel set up. The compensators are failing due to lack of lubrication. The newest upgraded compensator kit supposedly solved that problem.
If you go with welded crank and Timkin bearing set up , and big builds, then there are better choices.
 
#25 ·
same problem .....same answers. Went to 2 dealers and 1 Indy, they all told me
" well it's a Harley" . I am still looking to find a solution.
 
#29 ·
Calm down and breathe. What you guys are hearing/experiencing is called gear/drive train lash. All drive trains/gear sets have a built in lash/tolerance to absorb the energy that is generated when the load on one or more components of the drive train is loaded/unloaded. When you are tooling down the road at speed, the engine is driving the rear wheel with the energy from the engine to the rear wheel remaining fairly constant on the top front segment/teeth of the crankshaft sprocket and the top rear segment/teeth part of the transmission sprocket. Therefore the drive(primary) chain is taut on top and slack on the bottom. (the auto tensioner in the primary "compensates" for this slack by pressing up on the bottom of the chain.) If you drop off the throttle suddenly the energy from the drive train is suddenly "reversed" with the rear wheel now driving the engine sprocket. This shifts the energy from the top front segment of the drive sprocket to the bottom, and therefore shifts the slack from the bottom of the primary/drive chain to the top and causes a "reversion of forces" on all of the components of the entire drive train. It is this reversal of forces that you are hearing. Harley uses some fairly substantial (large heavy)gear sets and they do make noise when the forces are shifted.

The "shock" to the drive train should be compensated for by the tensioner and type of transmission/primary fluids you use. Now, the argument about the HD vs Hayden tensioner is all about how the tensioner does its job. Personally, I am a fan of the Hayden tensioner as it is constant (spring loaded so it stays in contact with the chain when loaded or unloaded), whereas the HD only self adjusts up or tightens.

Try this, take the bike out for a ride with the stereo off. in any gear, roll on the throttle then snap off, you will encounter Gear/drive train lash. The amount of noise/clunking should be fairly constant throughout the gears. You can also sometimes hear this lash when you go over a large road defect. If it seems excessive, argue with the dealer. If you have an ESC let them deal with it. If you can, swap out the HD tensioner with the Hayden one. Not sure it will eliminate all of the lash but it will help. try another gear oil in your primary as well as some are specially formulated to absorb shock loads better than others. Ask 10 people here what they use and you'll get 10 answers. My advice - try 'em all but note haw each one works for you then stick with the one that you like best.
 
#30 ·
That's what was explained to me in a much less scientific way by the service writer, this is why I hate diagnosing problems with a friend over the phone! Your explanation makes perfect sense as did his which is why I wasn't fresking out about it, next time I'm in the poconos I will have my buddy ride it and decide if it's a problem or not


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