456 Auto Transmission Fear

there are tons of these cars parted out... so finding one from a yard should be easy

the tranny is a GM unit.

 

Basis of transmission is GM 4T80E with a custom designed bell housing (to account for placement under the back seats). Majority of internal parts are replaceable with GM parts but NOT ALL. Rebuilds are possible without problems other than the need for custom gaskets. Labor is expensive since several hours are needed to remove the rear bumper assembly to allow access. This transmission is very sturdy and dependable; don't let the "horror" stories deter you from considering a 456M GTA purchase with a good recorded history.

 

There is a really good thread on what standard GM parts can be used to keep the Ricardo/GM GTA transmission in good shape. Thought I saved a Word version of it but cannot find it. Definitely worth a search for any GTA owner. We used to get good advice from the original designer of the system, but unfortunately he is no longer with us.

In general, these transaxles have been very reliable.

 

Taz, this might be the thread you're looking for: https://www.ferrarichat.com/forum/threads/456gta-transmission-service.455592/.

Chip McLeod is the SC FCA President and has a lot of DIY experience servicing these transmissions, and if you search under his two UserNames ChipM, and chipmcleod you'll probably find some good stuff.

Adrian Turner was the guy with Ricardo who knew these transmissions inside/out and he posted some great information here, in 2-3 posts, but it appears they've been deleted or lost in space after the forum reorganization.

 

John- Thanks, and that also helped me find the Word document I knew I had. Renamed it and put it in another place so I can find it more easily.

 

it works just fine.
just buy it.

 

Buy. The car should be a dream to drive with a real oil pan automatic and that smooth engine.

 

whatever happened to the guy asking about a 6 speed swap...

 

Henry- I think he was discouraged. Much, much more difficult to do than a 575M F1 to 3 pedal change.

 

Every time I see a 456 with an automatic I quickly turn the page. But then it dawned on me that I really enjoy driving my automatic 3 series BMW. Maybe it would be a totally awesome experience. Certainly worth checking out.

 

The corvette and 456 have the same layout. If the 456 took a dump I would try and retrofit the A6 vette box into the 456. All you would need is a custom torque tube/drive shaft/ adapter plate made. I would use a vette torque tube unit and modify the front to mate to the back of the 456 motor. Lots of people make custom bellhouses for all kinds of swaps so it is nothing new. The side-efect would be a killer tranny and paddles that shift about as fast as early 360 ferrari technology because the A6 is tuneable in the aftermarket.

 

FBB- Even though it only has a 4 speed automatic, the transmission is very well adapted to the torque characteristics of the F116 V12. A 6 speed, or even one of the new 10 speeds fitted to C7 Corvettes, would be very interesting, though.

 

I was completely the opposite. I wanted a GTA for highway travel and inside DC’s beltway. It is a dream to drive.

 

I like your imagination and ideas. Slightly off the topic, my dream is to make a custom belhousing so that a 456 V12 will fit to the transom of a MerCruiser Bravo drive unit. They have to flat points within the boat (on the transom) that you put the MerCruiser bellhousing onto and put a long bolt through to fasten the engine to the boat + two more engine mounts under the front half of the engine. This way, one could have an awesome engine that revs much more than the GM 5,7 - 6,2 and 8,1 liter V8s that Merc use. Also leave the problems of single camshaft and pushrods behind. And save a lot of weight going from cast iron to Italian alloy

 

That would be as cool toy! But Ferrari motors can barely survive the street. The water would kill one and quickly. Get a good radio and "vessel assist" or stay within sight of shore. Personally, I love Ferraris, maseratis, alfas and ducatis but I don't want to be in an Italian boat or an Italian plane.

 

I rely 100% on this generation V12 with mechanic throttle body. The solution to corrotion is to have a heat exchanger that cools the coolant with seawater like on most other boat engines. It should be possible to cut a GM marine housing and weld it to the clutch housing.

 

I took a chance and bought a '19 mustang GT with 10speed autobox as my next SCCA racecar. I took it out with 100miles on the clock for a trackday shakedown before stripping it for its rollcage. I am totally impressed with the 10 speed. The Ford/GM collaboration on the 10 is well done. Their target was the porsche PDK and they nailed it. The 10speed does everything the PDK does manual shifting just as fast and holding gears with slushbox reliability and only oil change as maintenance. It even uses cheapo Ford HTLV trans fluid! I just need to figure out where to mount the giant trans cooler to keep temps in the zone and I'm good. But cooling is a problem with any streetcar turned racecar. I honestly don't know why GM is putting the DCT in the C8 vette when their 10speed is so good.

 

FBB- I think the 8 speed DCT weighs quite a bit less than the 10 speed automatic and does not require a torque converter so takes up less space, too. It shifts faster, too, as long as the next shift is in the correct direction for the preselect. Shift times are so low in the latest DCTs and autos, though, that there is not that much difference.

 

You know, I have been thinking the same thing for years! A proper auto would really liven up a GTA