Clunking in the primary : V-Twin Forum: Harley Davidson Forums

MadCity · 10-13-2009, 10:28 PM

I'll begin by admitting that I'm a mechanical clutz, I have only a few tools, and I don't do any wrenching on my own bike. A few weeks ago I noticed that, after shifting into first, my bike would begin to move normally as I disengaged the clutch, then before reaching enough speed to shift into second the bike would lurch a bit with an audible clunk that sounded like it was coming from the primary. I assumed the primary chain may have had too much play and needed to be adjusted. I took it to my dealer, and one of the techs did adjust the play in the chain. That helped, but now and again it still happens, particularly when the bike is cold and I'm ascending an incline out of the parking garage I park in during the day. Today I took the bike in for an end-of-season oil change (they're calling for snow showers in the local weather forecast, and I'm ready to throw in the towel), so I had the tech check the primary chain tension again. He said it's right on. On the way home, it did it again, lurching between first and second gear. Any ideas?

hbmc · 10-13-2009, 10:40 PM

well what did the tech say? Curious.
When Chain is cold it is sloppier.... after warm up still?
Also I gotta say a clunk is more like engaging a gear... A clunk?
a clack or slap is different (like chain slap would be from a loose chain)
When the Clutch is pulled in or engaged? Or ? Cannot here or see what you are seeing / hearing.... tech took it for spin I am sure. He had nothing to mention?
How about is it at shift point from shifter? Pawl Adj---doubt that. But could be... see if the shifting mechanism is all good and tight. DO NOT loosen any of those nuts especially the pawl cam adjustment nut found deep down by the shifting shaft.

If you can be more expletive of the occurrence and when and what Exactly you are doing. Or strap a video cam on the floor board and give us a 1-5th easy up and down and upload it to photobucet. maybe we can help a bit better??
Regards

MadCity · 10-13-2009, 10:55 PM

The tech said he couldn't replicate the problem nor did I think he could. It only seems to happen when the bike is cold. And, like I said, it tends to happen most often when I'm starting out in first gear, then adding some gravity load by running up an incline. I'm not sure what the difference is between a clunk and a clack. One of the other techs wondered about my final belt drive tension, checked it and it seemed okay by him. This does not happen with the clutch pulled in. It only happens when it's engaged and the bike is in first gear. The shifter seems to be behaving normally.

hbmc · 10-14-2009, 12:22 AM

you may have got it with the chain adj but I have heard folks chatting about comp nut getting loose? Which btw is the nut that keeps the front sprocket to torque specs which inturn is connected the chain. Ride it if it worsens then get a P gasket and check it out?

FXDRYDR · 10-14-2009, 07:50 AM

Sounds odd. I'd suspect the comp nut.

FWIW - I'm no wrench either but I pulled my primary and if I can do it, any one can. Not a bad job provided you have basic tools, access to a torque wrench and large sockets, a service manual, patience and time.