TH-400 help

[Tom Sharpe]

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)

Forces the trans into second gear. (+12)

> 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...

OK.

> 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?

It tells the trans MAP for shift point determination and raises internal
pressure to eliminate slipping.Only if it blows out!!! (yes)

> 4.  How do you adjust the wide open throttle shift points?  I realize that
> the trans must be disassembled.

Change the governor weights/springs. Get a kit from TCI for the whole trans.

> Regards  Tom S
> Thanks a lot,
> Brock