TH-400 help

[Don.F.Broadus at ucm.com]

To use a TH 400  for Vehicle Speed Sensing (VSS) input to the ECM. Remove
the 4 bolts holding the tail shaft housing. Remove the speedo drive gear
from the output shaft. Install speed sensor gear (40 tooth) AC Delco part
number 8655315. Reinstall the tail shaft. The speed sensor pick up can be
purchased from AC Delco also but I don't have that part number. You will
need to see if the output of the pick up (AC) can go directly into the PCM.
You can buy a modulator control from B&M that is made for Turbo
applications, its mechanical and adjustable .    
 
Don   

> -----Original Message-----
> From:	Shannen Durphey [SMTP:shannen at grolen.com]
> Sent:	Tuesday, February 23, 1999 8:43 PM
> To:	diy_efi at efi332.eng.ohio-state.edu
> Subject:	Re: TH-400 help
> 
> Possibly someone can :)
> 
> Jennifer and Brock Fraser wrote:
> > 
> > Possibly someone can help me with a TH-400 application.  I haven't ever
> had
> > any dealings with these units, so I have a few questions...
> > 
> > 1.  The trans has a wire labeled "kickdown switch".  What does this do,
> and
> > do you ground it or supply +12 to activate it? (I assume +12v, since
> there
> > are no other wires and grounding could be through the case)
> 
> When you step on the throttle, it closes a switch supplying 12V to the
> downshift solenoid.  You get downshift.  Like the kickdown cable on
> other trans'.
> 
> > 
> > 2.  Does anyone see any problems with deleting the speedo sensor, since
> the
> > speedometer on my car takes its reading from the differential, and I'll
> be
> > using a manual transmission calibration with the PCM... (96 LT1)  I
> think
> > the only thing that a manual cal uses the speedo for is idle speed, and
> I
> > can do without that.  Error codes aren't a concern...
> > 
> Deleting?  Leaving disconnected, no.  Removing it and leaving a gaping
> hole, yes.
> 
> > 3.  There's a modulator on the side of the case.  What does a modulator
> do
> > when it sees boost pressure?  Should I use a check valve to block boost
> from
> > going to it?
> > 
> Modulator adjusts line pressure to make shifts harder/softer with
> more/less load.  Also plays a part in determining which gear trans
> downshifts to when throttle is stomped, and upshift points.  If you
> use a check valve, the line to the modulator needs to be vented so
> vacuum isn't trapped in the line.  Also, they make plugs to replace
> the modulator.  You might investigate this route.
> 
> > 4.  How do you adjust the wide open throttle shift points?  I realize
> that
> > the trans must be disassembled.
> 
> Modulator + governor springs.  Look for a "Shift Kit" by TransGo,
> there's goodies + good info there, and price is right.  No
> substitutions, either.  Also try to get A1 Trans or B+M catalogues.  I
> can dig out some phone #'s for these guys tomorrow.
> 
> > 
> > Thanks a lot,
> > Brock
> No problem.
> Shannen