# turbo 400 shifting issue



## redhotgto66 (Sep 11, 2021)

got kind of a wierd problem spring up, my 65 has a 1967 400v8 with a turbo 400 behind it. the kickdown was never installed so it was really sluggish upon accelerating. i installed a B&M kickdown switch, also put on a new vacum modulator hose at the same time (because the old one was horrible looking) after doing this took it for a spin, the kickdown works great but after a few shifts 2nd gear just went away, it skips 2nd and slips till 3rd can kick in. so 1st thing i did was undo everything i had just done but it did'nt change anything, still misses 2nd gear.
i have been told maybe its a valve body problem like a sticking valve, some say the trans is toast.
any ideas ?


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## Lemans guy (Oct 14, 2014)

Since that hose was so bad your vacumn modulator may be toast as well. Those are about $15 dollars and you can install a new one yourself. You might just try that and see before you have to dig further into it.










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## Lemans guy (Oct 14, 2014)

Have you changed the trans filter and fluid?…could be all bummed up in there, just something else you could do before more expensive trans work needed…


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## redhotgto66 (Sep 11, 2021)

thanks for the ideas, i was gonna try them both just wanted some more ideas. i had one tranny guy say to put lube gaurd in there and drive to maybe un stick the vavle body, has'nt worked yet. so onto other plans
thx


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## Sick467 (Oct 29, 2019)

I can't say what problems a collapsing modulator hose would cause, but make sure your mod hose is good and stiff so that it does not suck shut. I have heard of folks using light duty hose that kinks or collapses. This causes troubleshooting headaches since you can't see it collapsing/kinking while driving the car.


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## redhotgto66 (Sep 11, 2021)

the new hose is metal, with only a small rubber hose at each end to connect to carb etc


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## armyadarkness (Dec 7, 2020)

Btw. Same car same setup, new modulator lasted two days and left me stuck. It was a top tier napa too


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## redhotgto66 (Sep 11, 2021)

armyadarkness said:


> Btw. Same car same setup, new modulator lasted two days and left me stuck. It was a top tier napa too


was it shifiting wierd also ?


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## redhotgto66 (Sep 11, 2021)

well i installed a new vacum modulator, and added trans x lubricant, still not really a difference thats noticeable. sometimes its a little better but not consistently, so maybe the lube is starting to work ? when i smash accelorator in 3rd it shifts into 2nd or passing gear so it works just not on its own, leads me to believe its a valve body issue ?


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## PontiacJim (Dec 29, 2012)

redhotgto66 said:


> well i installed a new vacum modulator, and added trans x lubricant, still not really a difference thats noticeable. sometimes its a little better but not consistently, so maybe the lube is starting to work ? when i smash accelorator in 3rd it shifts into 2nd or passing gear so it works just not on its own, leads me to believe its a valve body issue ?


Have you checked the down-shift switch under the gas pedal - power/adjustments?


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## redhotgto66 (Sep 11, 2021)

well this car didnt have a switch on the gas pedal, i had to install a B&M unit on the intake, it was right after doing this that the trouble started, and yes ive unhooked it but problem still remains.


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## armyadarkness (Dec 7, 2020)

redhotgto66 said:


> was it shifiting wierd also ?


In my case, mine was leaking at the O ring and it was cheaper/ easier to buy a new modulator than to replace the O ring... so I bought a brand new unit from NAPA and it failed in a day.


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## armyadarkness (Dec 7, 2020)

redhotgto66 said:


> well this car didnt have a switch on the gas pedal, i had to install a B&M unit on the intake, it was right after doing this that the trouble started, and yes ive unhooked it but problem still remains.


Well it's foreseeable that you might have fried the solenoid when doing your wiring. But that's just for the kickdown, not the shifting. Post a few pictures of your B&M setup.


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