04 Sportster noise

I replaced my primary oil about 2 months ago with a quart of 20w 50w castroil and I notice a small chip in the old oil. 2 months later its making a SSSHHHHH noise intermitenly from what sounds like the primary. I changed the oil again expecting alot of grindings in the oil but it looked pretty normal this time. I'm about ready to yank the cover, but before I do I wondered what you guys may think. Bike only has 6K miles, maybe a bolt came loose and is rubbing or could it have been the oil?

You really should be running a gear oil in your Sporty primary....you're asking a lot of engine oil to lube and protect tranny gears, primary chain and sprockets and don't forget your clutch.Pretty harsh enviroment for an engine oil. A 75-90 gear oil with LSD(Limited Slip Dif) additive pack suitable for wet clutches is what the HD SportTrans fluid was...now it's Formula+ HD sells.

Good point, I didn't know that the primary and the gears share the same oil. It didn't start making that noise until after the last oil change so I'm incline to try a heavier oil and see how it does. I'll also get a stethescope and see if I can better isolate the sound. I'm almost leary of doin a teardown looking for a noise maker.

It could just be the primary chain is loose,they need to be checked and or adjusted every 5000 miles, when its service time, which you are... 6000 miles. Factory service manual and parts catalog are your 2 best tools, it`ll give your specs on primary chain free play.

Keep the bike completely straight up, even slightly tilted the opposite way, or the oil will spill all over from the primary.

I'll be checking the chain tension tonight. I also got a stethascope that I'll be using to hopefully isolate the noise. I did try fresh tranny oil but made no change in sound. Do you think it could have damaged the tranny by running 20w 50w motor oil in there for about 1k miles?

No...not for just 1000 miles...I think chain free play is 3/8"-5/8" hot and 5/8-7/8" cold but check manual to be sure. I've run Castrol 80-90 gear oil in my primary and tranny in the cop king, couldn't find 75-90, less expensive than HD oils. It'll say on the bottle "suitable for wet clutches".
Sporty's are tough bikes....you really gotta try hard to hurt one.
Keep us posted on what you find.:devil:

I checked the primary chain deflection while hot and it was about 3/8". I rode the bike around a bit and tried the stethascope on it and while setting still I noticed alot of clatter from rocker boxes and cam but nothing I haven't gotten used to. But when the bike was rolling I was getting that sound and with the stethascope it was almost like a squeel. It was coming from the bottom end but I couldn't tell if it was the cam side or the primary. But it did seem to be closer to the crank area.

I assume your talking about the rear brake rotor? I did check, it seems tight. I also checked the rear sprocket and it also seemed tight. I started to wonder about cam bearings but I hear it when moving only so it takes me back to the transmission or primary. I think I'll ride some more tomorrow with a scope on it and see if I can better hone in on the noise.

I think chuck meant the alternator rotor, possible the comp nut backed off a bit, if you isolate the noise to be in the primary side I think you'll have to pull the cover and take a closer look..make sure it's not your brakes(sticking caliper/warped rotor)...can be hard to tell where a sound is coming from with the bike moving.When you have the bike moving and you hear the noise, try your brakes and see if it goes away.

Ah, ok that makes sense. I'm gonna pull the cover today and was wondering if you can feel the rotor without removing the sprocket? I've got the cover off and I can't touch the rotor with the sprocket on. I did notice a bit of rock in the clutch shell sprocket. Is that normal?

After pulling the sprocket loose I could feel the rotor and it felt tight. At this point I'm not seeing anything that would be making this noise so it's goin back together and I'll trouble shoot it the old school way. I'll ride it like a dog till I can trace the missing part through the hole in the case...

I decided to look for a different oil for the primary like you said Lucifer and wanted something rated well and that I could buy local. I looked for Amsoil or Redline but couldn't find local. I ended up with Mobil 1 syn 75w 90w for the primary and decided to do same for engine so I got Mobil V twin 20w 50w for the engine. I took the bike for a ride today and the noise is pretty much gone. Maybe tinkering around in there made the difference but I really think it was the oil, go figure. Thanx Lucifer

That is good news!!!Glad it was a simple fix

I think that I may have to try that because I have been getting some of the same strange noise. I took mine to an indy shop, not the one that I usually do because he was really busy, and the other shop said that everything seemed good. I have some work to do my bike tomorrow anyways, might as well change some fluid while I am at it.