Overdrive-4

I'm starting to hear rattling noises in 2nd and 3rd gears from my current A833. Worst case, I'll rebuild or replace. In the case of the latter, does anyone have experience with a later model A833 Overdrive-4 transmission (pros, cons, etc)? Curious about how the change in ratio for 3rd and 4th gears worked on a street cruiser, durability, etc. Any clarification would be appreciated.