My shift lever was feeling a bit "notchy" between gears, at 50,000 miles. I had the same issue with my Honda ST 1300, so I tried the same fix. Drained out the Blue Ray 10-40, replaced filter with Bosch 3300. Added 4 1/2 quarts of Rotella T 15-40. After about 100 miles, I noticed smoother shifting and the notchy between gears much less. A 10-40 is fine for the engine, but seems to be too light for the transmission over 50,000 miles.