The Harley shifter system as a whole has been faulty for many years now but the Harley-Davidson Motor Company remains silent about it. However, every Harley dealership mechanic who's been around more than a week will readily tell you that the Harley shifter system fails routinely and is problematic for many riders. (see video below)
Many Harley riders I know have had this issue while out on the road riding long distances and you can guarantee when it fails it will be in the middle of nowhere. In this video, I show you how to properly inspect the Harley shifter system and all the failure points. If you already have a shifter issue, I show you how to repair it. I had a Harley shifter arm failure outside of Cheyenne, Wyoming on my 13 state trip last year and I don't want it to happen to you.
Up at your Harley toe/heel shifter is the shifter shaft they connect to with a clamp/bolt type system. There are splines on the shifter levers and shifter shaft. That shaft then goes through a housing to the inside of the primary housing. On that side, the front shifter arm bolts to the shifter shaft, again both having splines. At the top of the front shifter arm is where the shifter linkage attaches. And that shifter linkage then runs back to the rear shift arm that then goes to the transmission.
Where the shifter shaft goes into the front shifter arm is where things go bad. Even if the front shifter arm clamp bolt is plenty tight, the splines slowly work against each other over time due to too much play and improper tolerances in my opinion. The splines eventually strip out and fail, thus you can no longer shift. There are no big warning signs leading up to this unless you get down and inspect your Harley shifter system.
Where the bolt goes through the front shifter arm clamp there is a channel in the shifter shaft that the bolt must align with. Over time, those threads on the bolt will actually wear and align with the shifter shaft splines and then the front shifter arm will fall off the shaft. There will be visible mashing of the bolt threads if this happens. Replace that bolt if that happens.
The stock Harley shifter linkage will fail on you at some point. I strongly suggest you replace your shifter linkage as soon as you by a Harley with a quality aftermarket shift linkage. There is no warning to this and your linkage will just fail at some point.
The cheap stock linkage is a system of balls that pivot in the ends of the actual shift linkage shaft. The shaft presses onto the balls, which pivot around and overtime just wear out. At that point, your stock Harley linkage will fall off the rear, front, or both, and will not press back on. I have seen this happen to many riders on long road trips. Carrying our Cruz Tools Emergency Roadside Repair Kit from our online store, some zip-ties, and some duct tape will get you on the road until you can replace it.
The quality aftermarket shift linkage uses Heim joints and actually bolts on to the front and rear shifter arm. This is a much more robust system and removes the failure points.
Make sure all the bolts are tight on the shifter clamps and arm clamps and use blue thread lock on all of them. Also, when you put your shifter shaft back through the housing, make sure to put a bit of anti-seize grease on it.