This started as a different problem, but ends up tranny related....so....

I had some problems tonight.Wewent and ate, and when we got back on the bike, the speedo started acting very erratically. On acceleration, it would kinda read, but was wavy, and same during cruise conditions; but during coat and stopping, it would drop to zero, even at high speeds. Then it got a bit worse and the turn signals stopped cancelling and it started backfiring and stalling in traffic. Got on the interstate to avoid some traffic, and accelerated kinda hard and got the check engine light and the speedo stopped working altogether.

SO....got it home and looked in the book and on here for DTCs, and read a VSS low code. Makes perfect sense. Also saw that a cause for erratic speedo operation is a contaminated sensor or loose wires. well, the wires weren't loose, so I pulled the Vehicle Speed Sensor and it had a small bit of gray substance on it, almost a sludge, but it was such a small amount, it was hard to tell the exact consistency. it was really just enought to fill the 2 tiny grooves on the VSS and a very light film on the end. Cleaned it off and put everything back together. Bike is back to normal now.

I am assuming it is metal sludge from something inside the tranny. The oil has a normal look to it, so I don't imagine there's a lot of it in there, but might it be bad, or even a serious concern?

 

.....06 Wide Glide--2300 miles.

 

My 1999 Dyna had the same problem as well a few years ago. It also had the grey sludge on the speed sensor as well. I just cleaned it and it worked fine ever since. The transmission does not have that much sludge and a little sludge won't cause any problems in there. I just pull the sensor every 10,000 miles and clean it. Because, I hate having a problem when I least expect it and I am on the road somewhere...especially when I might could have been prevented.

From my experience, motor oil used in the transmission develops sludge at a faster rate than the standard gear oil does. My experience is based on owning lots of bikes and riding nearly everyday of the year. And working on individuals bikes as well.