'06 Road King Classic,15,000 miles. I was on a weekend ride a few weeks ago. Started hearing a noise that sounds like a small turbo charger winding up every time I shifted into 4t gear. If I run in 4th at a steady speed you don't hear it as much or not at all. 1-2-3 and 5th gears are quiet. Only hear it in 4th and its loudest when accelerating. Changed the transmission fluid today the magnet on drain plug had a couple of small filings on it. This must be normal because the service manual said to be sure to clean the magnet before inserting it back into the transmission. So, my question is, whats causing this sound in 4th gear and is it anything to worry about? Thanks for your time, FLHFred

 

I have an 06 Ultra similar noise in 4th. Some have stated the newer 6 speeds have a noise in 5th. I guess HD decided to let you know you have one more gear!

I had my tranny checked and flushed by my indy. He also put in Spectro Synthetic tranny fluid. Still have the noise, and the last drain of the tranny fluid looked like it was still new. No chips, shavings etc.

 

I have a 2006 Road Glide that I bought new and now has 35,000 miles on it. It always had a strange winding noise every time in 4th gear. Never had any issues with it and I always know when I'm in 4th. I've run Harley tranny fluid, Torco, Ams oil, it never changes.

 

Its the exact same noise everybody that has a 6 speed has been complaining about in 5th since 07 and the same noise that Ive been telling them 5 speeds had in 4th, no big deal.

 

'05 FLHTC and have the same noise in 4th gear also. Just under 30,000 miles.

 

same thing with my 06 ultra 85000 miles no problem

 

Change to Redline transmission oil and the sound will be gone.