FG Gearbox Upgrade 5 to 6 speed


4WDaus "tralia"
Hi guys
A friend who is a mechanic made a comment the other day which wondered if anyone had looked into, could a Mitsubishi Rosa 6 speed gearbox be put into a FG649 to replace the 5 speed? When buying filters I have noticed they do share the same engine.
Appreciate your feedback


Have thought about doing this for a while. 6 speeds were/are also used in bigger canter FE so it should all bolt in, except for the transfer. May have to run divorce unit, something like a NP205.
Gearbox Model number has a S5 at the end, 6speeds are S6 for the equivalent box.
Tcase does represent a slight issue (well for me anyway), high ratio is 1.09, but basically any other tcase you can get will be 1:1. I guess 9% taller high ratio will be fine for most canters, but mine with the big XZLs is already almost too tall, doing 2150@100, another 9% on top would be too much.
Best solution I found to that would be to go from 5.29 diffs to the fg649 5.71s which would be 8% I think, so bringing it back to where it is now.

Aussie Iron

Can not see why it can't be done. Yes it would probably need an adapter plate to mount transfer case and a new rear shaft made. Someone supply me with a gearbox and I'll get it done and fitted to my Canter. That way we will know it works.

Just another Gear to Change,

Aussie Iron

Is it a typo in that ad?
Typo for what. The motor is a 4D35 4.6 litre (same as 4D33 but with larger bore non-turbo as standard) the same as a Rosa Bus. The gearbox is a 6 speed out of a Rosa Bus and looks like parts are available to fit the 2 speed transfer case. So standard from Japan I can see that.
There was an import from Japan that went to the states there a while back that had a 4.6 litre engine and I did enquire for an engine prefex but never ended up with an answer to that, but would presume that it was a 4D35. Maybe it also had a 6 speed.