I'm currently on my second oil change with Rotella T6 5W40 Synthetic and have a occasional "missed shift into second gear". It is definitely rider error in not "crisply shifting. If you are paying attention to operating the 6and not daydreaming
the trans works as designed. I've had several "heavy cruisers" and one required a fluid change on the hydraulic activated clutch to improve shifting.
Not sure but after nearly 20K miles of riding I may change the DOT 4 on the 6. Probably wouldn't hurt and may actually improve things![]()