Transmission problem on 79 TA

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79 Trans Am - 27 Mar 2004 18:09 GMT

My TA has been sitting since last October and hasn't been moved (thanks to
the lovely UK winters), today i've replaced the distributor cap, rotor arm,
plug leads, drained & refilled the radiator, and i've changed the carb
vacuum hose + a couple of others that were looking tatty.

So after doing all that i decided to take it out for a blast, unfortunately
it wont change into 2nd gear. It used to change at around 25/30mph then
change into 3rd at about 50mph. 30mph and you can tell it needs to change
up, boot it upto 50mph and it changes into 3rd, slow down and it goes back
into first. I've checked the transmission fluid from the dip stick & its as
it should be (clear/reddy colour).
It will shift into gear, reverse, park, neutral, drive, etc you can feel it
engage so its not a shift problem it just wont change into 2nd when on the
move.
Someone mentioed the vacuum pipe to the modulator? haven't got a clue to
where to start looking though.

Any ideas?

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=AB Paul =BB - 27 Mar 2004 19:43 GMT

> My TA has been sitting since last October and hasn't been moved (thanks to
> the lovely UK winters), today i've replaced the distributor cap, rotor arm,
[quoted text clipped - 14 lines]
>
> Any ideas?

See if the downshift cable is stuck in downshift position.

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79 Trans Am - 27 Mar 2004 20:04 GMT

> > My TA has been sitting since last October and hasn't been moved (thanks to
> > the lovely UK winters), today i've replaced the distributor cap, rotor arm,
[quoted text clipped - 16 lines]
>
> See if the downshift cable is stuck in downshift position.

Haven't got a clue where that is though.
Few people have said its more like a vacuum hose into the intake manifold
from the modulator.

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=AB Paul =BB - 27 Mar 2004 21:55 GMT

> > > My TA has been sitting since last October and hasn't been moved (thanks
> to
[quoted text clipped - 28 lines]
> Few people have said its more like a vacuum hose into the intake manifold
> from the modulator.

It could either or both. That trans should have both.
Could be other things, too, but start there.

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Joe - 28 Mar 2004 00:37 GMT

The cable is very obvious. There are two cables connected to your
carburetor. One of them comes from the gas pedal. The other goes to the
transmission. Start at the carb and you'll find that no problem.

The vacuum hose is connected to a steel pipe which is bracketed to the
engine-transmission bolts on the back of the engine. There may be other
steel pipes with vacuum hoses hooked to them. If so, pick the one closest to
the firewall and check to see if it is bolted to the back of the engine.
This pipe must be connected to manifold vacuum, which I'm sure originally
came from the back of the carb. However, everything other vacuum line comes
in there too, so that's a lousy place to look for a vacuum hose. Look for
the steel tube instead and follow that toward the manifold.

79 Trans Am wrote:

> > 79 Trans Am wrote:
> > >
[quoted text clipped - 30 lines]
> Few people have said its more like a vacuum hose into the intake manifold
> from the modulator.

It could either or both. That trans should have both.
Could be other things, too, but start there.

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