2008 flhtc.
When I first purchased this bike the primary had a low speed whine that was
quite evident at idle. After several thousand miles the noise was much quieter and all was well. After a slow 100 mile ride yesterday the whine is back as bad or worse than before at idle again. Tried again this morning and it was pretty quiet when cold but came back after heating up for an hour or so. I was told when I first got the bike to give it time to wear in and loosen a little and it would get quieter, which it did. I am now wondering if the auto chain tensioner on this 08 could have ratcheted up a click to tighten the chain and that might be what is causing the whine. Changed primary fluid a thousand miles ago and went from syn 3 to mobil T racing 10/40. Sounds like a parakeet in there.
Thanks

 

The HD version of the auto-tensioner keeps the chain as tight as a banjo string. Another case of the MOCO fixing something that was not broken. I took mine out and threw it away. Installed a Hayden M6, which I have ran in the last several bikes I have owned. Never have had a problem with the M6.

 

I recently had the same issue and am taking to the dealer in a couple days. Bike only has 2000 miles on it.

 

Make the lazy dealer replace the chain and maybe the sprockets.

 

Since I posted this, I have had the chance to stop at 2 dealers in another state and both were nice enough to have a tech listen to my primary and they both said that the noise was normal for bikes with the auto tensioners. One tech even let me listen to his 09 classic and it had a slight whine also. He thought what I did originally. That the tensioner just ratcheted up a click and is tight right now but it will probably quiet down when it stretches a little. Please let me know how you make out at the dealer.

 

I spoke my opinion above. You bet it's tight...too tight and as soon as the shoe wears enough...it will ratchet up again and be too tight again.

Toss it!

 

My 2007 FXST has a very noticeable primary chain noise which gets worse by adding gas (increasing RPM) I don't know if this is a problem I need to be concerned about or no

 

2 things:

1. Open up the derby and change the oil to a 20w50 like syn3 or mobil1vtwin and while you are in there check the tension on the chain. Might be loose. If it is loose try some acceleration-deceleration in 2nd gear and see if you can get the tensioner to rachet it up tighter. If that doesn't work then you need to open it up and check the compensator & clutch hub nuts and the tensioner itself.

2. Mine had a very pronounced whine and I changed the oil to a 50-50 mix of redline MTL & MT90 after which it disappeared. The mix is about the same as a 38w oil.

 

link didn't work

 

OK, I'm also having a whine. It started a few days ago after hitting a pot hole at 45mph. its most noticable while slowing 4th 3rd 2nd gears, Could this be caused by the auto tensioner. 2007 heritage w/ 11k miles.