That's right. The J type is physically bigger and the planetary gear and annulus are bigger. The unidirectional clutch was lifted straight from the D type.

However, whilst the cone clutch is physically bigger on the J type, the actual cone itself is aluminium. On a D type its steel. I've seen the cone clutch ripped to pieces on a J type. On a D alll that tends to happen is that the whole thing becomes so hot it stops working, but it will still transmit drive in non overdrive mode.

Of course some seriously uprated bits have been made for theb J and if you must have a really strong overdrive then a J is a good starting point. In standard form the idea that a J is better is frankly Bull Shit.


Regards


Pete