Ferrari Life Forum banner

1 - 7 of 7 Posts

·
Registered
Joined
·
1 Posts
Discussion Starter #1
Hi
I am a new member based in the UK. I am fortunate enough to own 5 Ferrari's including a 400i. It is a concours winning car, but I now want to use it more than show it, and want to update the 3 speed auto box to either a 4 or 5 speed auto.

Anyone got any experience or knowledge in making such a change? Any leads/ pointers/ ideas most welcome!
Thank you!
Geoffrey
 

·
Administrator
Joined
·
15,140 Posts
Hi
I am a new member based in the UK. I am fortunate enough to own 5 Ferrari's including a 400i. It is a concours winning car, but I now want to use it more than show it, and want to update the 3 speed auto box to either a 4 or 5 speed auto.

Anyone got any experience or knowledge in making such a change? Any leads/ pointers/ ideas most welcome!
Thank you!
Geoffrey
Geoffrey,

Never heard of this being done on a 400. However the auto box on the 400A was a US GM supplied unit. If you can find out what models GM used it on, you might be able to find an owner who has done the update.

Good luck.
 

·
Registered
Joined
·
3,627 Posts
The 400i uses a standard GM auto tranny.

You should be able to easily update to a 4 speed which may be a bolt on.

Your gear selector probably won't give you the individual gear choices, however.

The 456 used a GM gearset but in Ferrari's box design.
 

·
Registered
Joined
·
6,209 Posts
The 400i uses a standard GM auto tranny.

You should be able to easily update to a 4 speed which may be a bolt on.

Your gear selector probably won't give you the individual gear choices, however.

The 456 used a GM gearset but in Ferrari's box design.

the 400, GM tranny, was slightly modified for Ferrari's higher 12 cylinder torque.

Other than that, which is probalby just surplanting some gearing etc. I am guessing you can make the mods.

BUT, make sure if you don't modify that you might be replacing trannys as you go: toruque and all.

You are lucky actually, as I am somewhat looking, for having the option of a GT or A.

No GT's in NA unless federalized, which back in the day could run as hight as $100,000 and made no sense to do so.

rik
 

·
Registered
Joined
·
121 Posts
The 400i uses a standard GM auto tranny.

You should be able to easily update to a 4 speed which may be a bolt on.

Your gear selector probably won't give you the individual gear choices, however.

The 456 used a GM gearset but in Ferrari's box design.
No it's a GM box. They made a few changes to fit it to the 456 but that's about it. I'm just in the process of building one. The gearset is the same as they use in those terrible FWD cadillac's of the eighties! there is a bit of machine work to fit them to the hub, because there is a depth change, but that's it. Parts aren't readily available for those boxes anymore so i get bits from GM in the states.

As for the original question, i would be looking at the four-speed unit fitted to the daimler double six. The GM400 was used in the earlier cars and all they did was swap it out with the later box. The only issue would be with the bellhousing/torque convertor.
 

·
Registered
Joined
·
1,008 Posts
GJ - Did you undertake this project? I like the 400i, but with all the rare scarce parts out there, admire your courage in such an undertaking.

Pictures (this and your other cars)?
 
1 - 7 of 7 Posts
Top