I have a 2008 Nightster with 38,500 miles on it. Just recently replaced the clutch pack about a month ago. All has been fine until a few days ago. I was coming off the highway and went to downshift to 4th, with a bump of the throttle to rev match and the shifter would not drop into 4th gear, went to hit it again and it finally dropped into 4th but it was a really hard shift. No grinding or abrupt noises. All other gears, shifting up and down, are working just fine. Seems to only happen from 5th gear to 4th gear. I did a clutch adjustment already and that did not solve anything. Anyone have a idea what might be going on? Thanks!

 

39K mileage.
Just did a clutch.
Just did an adjustment.
Operator error, just making a bad shift, ruled out as the cause of complaint.
All fine until a few days ago...how many miles in between clutch install and the notice of the issue?

Your work would be suspect.
Only thing the internet can offer is to redo your work.
Remove and inspect clutch plates, re-adjust clutch, change the trans oil.
Look for broken springs, incorrect bolt torques, debris in oil, etc. during your inspection.

Also speculating with 40K miles.
Shifter shaft never bent?
Gear change abuses (racing for example) over it life?
Since you mention only 4th and 5th, gear teeth wear?
Some consider 40K high miles, others don't, and gear box wear could be suspect.

So, IMO redo your work and good luck.

 

When you replace/serviced the clutch, did you keep that crappy spring plate in the middle of the clutch pack, replace it with a new one or add a clutch kit that included the two extra steel and one extra friction disc? If you kept the original spring plate that is in the middle of the clutch pack, they sometimes don't last more than about 35K miles before the brass rivets fail and start putting small parts through out the transmission and clutch assembly.