Ferrari Mailing List: Re: 456 gt search

[Dave Craig (dave.craig]

Brian,

I think you might be talking about the BorgWarner T56 transmission's skip
shift "feature" (on Corvettes, F Body cars, and Vipers).  What this did was
to force a first gear to fourth gear shift if the throttle was not heavily
depressed and the rpms were low.  So if you are just puttering around, you
would always take off in first and then go immediately to forth (2nd and 3rd
were locked out).  This was a trick to create overly optimistic mpg figures
based on the government tests.  There is a very easy fix, basically removing
one connection from the trans and several places even sell a cheap plug in
kit for about $20.  
http://www.corvettesofhouston.com/product_info.php?products_id=68


But, what I found is that once you know the throttle input and rpms required
to overcome skip shift, then you just drive accordingly (heavy throttle and
higher rpms).  I just called it a driver's training aid.  After a month or
so of daily driving, I almost never hit skip shift again.

Dave   

-----Original Message-----
From: Brian Keegan [mailto:bks281 [at] hotmail.com] 
Sent: Wednesday, July 18, 2007 8:03 AM
To: Dave Craig
Cc: ferrari [at] ferrarilist.com
Subject: Re: [Ferrari] 456 gt search


   I believe the unit is a modified Borg-Warner and about the only parts
   available for them are the 3 filters for the ATF.

   "... parts were somewhere between difficult and impossible to get."  
   Ferrari is following GM's lead on this one.  A friend has a 1993
   Corvette with a 6 spd and virtually nothing is available for that
   gearbox either. IIRC, he told me to meet emissions, you are required
   to shift to 2nd by 25mph or the shift indicator (commonly referred to
   as a rev limiter) shuts you down.

   Brian
       ______________________________________________________________

     From:  "Hans E. Hansen" <FList [at] hanshansen.org>
     To:  Brian Keegan <bks281 [at] hotmail.com>
     CC:  The FerrariList <ferrari [at] ferrarilist.com>
     Subject:  Re: [Ferrari] 456 gt search
     Date:  Tue, 17 Jul 2007 15:52:34 -0700
     The auto in the 400/412 was a GM TH400 - a 3 speed.
     Could be wrong, but I don't think that the 456 auto box is GM
     derived.  I remember reading (Forza??) that it was sourced from
     a small company in Michigan that may no longer be around.
     The same article said that either whole units or parts were
     somewhere between difficult and impossible to get.
     Hans.
     On 7/17/07, Britt2Asa [at] aol.com <Britt2Asa [at] aol.com> wrote:
     > Sorry guys but I will chime in here. As much as the auto 400 is
     great (a
     > manual 400/412 is pretty much undriveable due to cluth weight)
     there have been a
     > LOT of problems with the auto gear box on 456s over here. A full
     rebuild at
     > 15,000 miles is COMMON! BTW you can get a NICE 10k mile 456 here
     for mid
     > 30's....Nobody wants them!
     >
     > Britt
     >
     > > Okay...
     > >
     > > But I did hear that if it ever had to be replaced it is very
     expensive....
     > >
     > > That's why I was questioning your choice in the first place....
     > >
     > > It is based on a proven GM TH trans, so it should be good.
     > >
     > > FG
     > >
     > >
     >
     >
     >
     > BR in the UK
     > 1986 328GTS (LHD 89,940km) Died August 19, 2006 Shrewsbury UK
     > 1980 400i (RHD 72,000 miles)
     > Searching for the right 512TR
     > 2003 BMW 530d
     > 1991 Alfa Spider S4
     > _________________________________________________________________
     > To unsubscribe or modify your subscription options, please visit:
     >
     http://lists.ferrarilist.com/mailman/options/ferrari/flist%40hansha
     nsen.org
     >
     > Sponsored by BidNip.com eBay Auction Sniper
     > http://www.BidNip.com/
     > and F1 Headlines
     > http://www.F1Headlines.com/
     >
     _________________________________________________________________
     To unsubscribe or modify your subscription options, please visit:
     http://lists.ferrarilist.com/mailman/options/ferrari/bks281%40hotma
     il.com
     Sponsored by BidNip.com eBay Auction Sniper
     http://www.BidNip.com/
     and F1 Headlines
     http://www.F1Headlines.com/
     _________________________________________________________________

   [1]Missed the show?  Watch videos of the Live Earth Concert on MSN.

References

   1. http://g.msn.com/8HMAENUS/2743??PS=47575
_________________________________________________________________
To unsubscribe or modify your subscription options, please visit:
http://lists.ferrarilist.com/mailman/options/ferrari/dave.craig%40sbcglobal.
net

Sponsored by BidNip.com eBay Auction Sniper
http://www.BidNip.com/
and F1 Headlines
http://www.F1Headlines.com/