Check the rubber muffler mounts. Mine drove me nuts until I inserted a piece of plastic milk container between the rubber mount and the bracket.

 

I was hearing a chirp when I snapped off of the throttle while doing 50-60 mph. After doling some research, I found that a lot of the time, a loose belt would cause the chirp so, while checking the tension on mine this morning, I found that I could deflect my belt from the bottom of the winder to the top with very little pressure. I guess thats about an inch of deflection. So, I consult the manual which gives a spec of 5/16"-3/8" deflection, cold, with 10 lbs pressure. Not having the gauge, I tooka chance and adjusted it by feel to 3/8". When I test drove it, it seemed to shift better and smoother. Maybe my imagination? Anyway, after riding for about 10 miles, I rechecked the deflection of the best and it was around 1/4". So, now I am thin king its too tight. What say ye ?

 

I have a 2003 Heritage and I had this squeak. Took it to the dealer and they had the bike for a few days and gave me the full gamut of things it could be. If I left it up to them I would have spent nearly $3000 in un-necessary repairs. I did let them replace the rear bearing, $300 but that wasn't the issue either.

Harley puts these plastic shrouds under the bike that are connected to the rear fender and are the same shape of the rear fender... sort of an extension of the fender and it bolts to the frame right next to the drive belt underneath. I was just about to lube up the belt with soap so the squeak would stop when I noticed that this fender shroud was worn away by the belt. I had the bike on the lift so I spun the wheel slowly and wouldn't you know it, the belt was ever so slightly hitting the shroud and making a noise. So I got my razor knife and trimmed the shroud 2" long by 1/8".

I would get this noise after about 8 miles of driving, after the engine was nice and hot. Hot enough that it would warp a plastic part out of shape. Since I did that little trim I haven't heard that noise.

Research will save you hundreds of dollars.

Ride Safer.
Ted
Motorcycle Men Podcast
www.motorcyclemen.us

 

I had that exact noise and it was a loose drive belt. Drove me nuts till I figured it out.