Join Date: Feb 2011
Location: Fort Worth, TEXAS
Knocking noise from drivetrain only when it's hot
On the way back from the Ozarks last weekend blasting down I30 at 70-75mph and the wife says she hears a squeaking noise over 72mph that goes away under that speed. We decide to switch bikes for the rest of the way home. I never hear the noise again for the rest of the ride.
When we get home it is pretty warm outside so we park the bikes on the street while we go inside for a cool drink and strip off our riding gear. After around 15 min or so I go outside and start her bike up to move it into the garage, drop it into first and move forward.
Immediately I hear a knocking noise that I can even feel slightly in the seat of my pants. Length of driveway is about 25-30ft and it knocks the whole way up. Last time I heard a sound like that was when I knocked a tooth off the first gear in my '66 Mustang that didn't have synchromesh on first.
I feel the final drive unit and it is pretty warm to the touch, but no hotter than the one on mine. PO said he did spline lube too. It was pretty late so I just finished putting the bikes away and cleaned up for bed.
Next day I rolled the bike around in the garage (in neutral) and no knocking sound. Open the final drive and it is full of oil. Changed the oil anyway, no sign of metal filings in oil. Our driveway is sloped so I coasted it down the hill still in neutral and on a good ways down the street and still no knocking. Started the bike and went for a 15min ride; no knocking. And it never made the squeaking sound again either. Very strange this is.
Wife rode the bike to work the next day (18 miles one way) and still no knocking. Went out for another ride together for around an hour; no noise, no problems. Had bikes parked on the street again for a few minutes while we moved the cars out the garage before putting them away. Jump on her bike, start it up and head for the garage...it's back knock, knock, knock.
If it was a busted tooth on a gear I'd think it would knock all the time and not just when it's hot. I can't be sure where the noise is coming from exactly because it's not that loud and the bike has to be rolling (and hot) to get it to happen.
Anyone got any ideas what I have going on here?
I figure I'll need to do a spline lube type tear down (already did that on mine) but I'm really not sure what to look for at this point.
Is there any possibility it could be a rear brake problem instead?
HIS - 2006 - Purchased with 1600 miles
Spline Lube, LED 3rd Brake Light in Sissy Bar, LED Brake Light Strobes, F&S Luggage Rack, F&S Engine Guard, F&S Extended Sissy Bar, Faria Voltmeter/VDO cup, 12v outlet, HF bulb
HERS - 2003 - Purchased with 4500 miles
Spline Lube,LED 3rd Brake Light in Sissy Bar, LED Brake Light Strobes, F&S Luggage Rack
F&S windshield, F&S Extended Sissy Bar, Faria Voltmeter/VDO Cup, HF bulb