Actually Cornes have already run diagnostics. Apparenty it's a solenoid that's gone on the blink.
GREAT news, happy for the solution seems like a very low cost on a [typically to be found I'm guessing] problem. This should help dispell the Auto nightmare everyone --who have no experience -- wolf cryers in the crowd. rik
While we all wait for Peter to get his diagnosis, I'll offer a few answers if I can. The 456 GTA transmission uses a number of components from the 4T80E GM unit. Parts like the solenoids, for example, are straight from the GM parts bin. Some (but not all) of the valve body is carry-over too. The design of the automatic trans element of the 456 unit was upgraded in several areas. Simplistically, the 456 boasts much greater torque than the GM internals were designed to handle and consequently many parts were updated and strengthened as required. THE TCU is a bespoke unit (GM product used a combined Powertrain Control Module) and the complete control system from strategy to actual software was developed for the Ferrari. The shift times were shortened dramatically to provide a sharper feel and to defend the friction featured items from the excessive heat that the higher torque generated and this again demanded further changes to other components. So, not all the "hard parts" that look like the T80 items actually are. The 4th drum is an example of this "upgraded" solution. A standard 4th drum is thinner in section and made of a different spec of steel, it will not last long in your Ferrari. You guys are quite correct in your assessment that no-one would set out to produce such a transmission from scratch for such a low-volume product, the cost would be prohibitive. As it was, far more was changed than originally intended and suffice to say neither Ricardo or Ferrari got rich from the programme. That said, in terms of keeping your cars on the road, it is possible to make it affordable I think by combining what I know and can provide with some local physical work. At the end of the day, we all need to make a living but it need not be painful for you. I guess I should just offer to diagnose the problems and supply the parts, that way I keep my lovely soft hands intact.
Adrian- Spoken like a true pro who wants to see his work continued and flourish, even if it is not a great way for him to get rich. Not enough of that feeling of responsibility going around now. Good luck in your future endeavors (sorry, endeavours), which I am sure will also be a credit to you. Taz Terry Phillips
Adrian, if I can make a suggestion, why not become a sponsor here on FC and perhaps work a deal also with Ricambi America? There are several potential owners of GTAs that are simply hesitant to make the move because of the fear of the unknown surrounding the automatic transmissions. With a known and reliable source for parts and service, this segment of the market could see some new life. Shipping a transmission half way around the world and back does not need to be prohibitively expensive. I ship large, heavy tool boxes filled with equipment around the world regularly and the cost of doing it, with the right knowledge and connections is quite reasonable. Just my two cents...
Alfredo- True, and it looks like most of the time the problem is a small part like a solenoid or sensor, not the geartrain and castings, which were deliberately over-designed. Taz Terry Phillips
Just in case it wasn't clear. I got a full overhaul of the transmission with solenoids and all consumables (plates etc... not really sure what those pieces were but there were a lot of them) replaced and a fluid change for the $6500 quoted (not a penny more), guaranteed for 1 year by Transtech. Car runs fine, No *related* problems since.
