I have a turbo 400 that was rebuilt with a shift kit.After driving for 15 to 20 mins.The trans doesnt want to come out of first gear.If you manually shift from first to second.It stays in first.The valve body was pulled down to check the valves.Everything moves freely.I put a brand new govenor in.Does the same thing.I`m going to pull the modulator which is new..To make sure it holds vacuum.After that i don`t know what else to do???Any help.

 

What brand shift kit ? Were any valves replaced ?

 

So ... it doesn't shift automatically at all, or are you only getting this problem when you shift it manually?

Do you know who built it?

 

Make sure the modulator is hooked to manifold vacuum and is getting vacuum. Also check your kickdown switch.

 

it stops shifting after 15 to 20 min.of driving.It seems like after it gets hot is when it does it.It is a trans-go shift kit.The modulator is new.I have to check that today.The guy that built it is baffeled.

 

Here is a possibility !!!!! I had a Trans-Go shift kit installed in my Toronado....... It did EXACTLY the same thing. When cold, it shifted like a dream, 3-4 miles and it wouldn't shift.
If they put in a valve from the Trans-Go kit, put the stock valve back in to see if it changes things. We went through the multiple governor, modulator changes and nothing helped. The Trans-Go valve was examined and nothing wrong was visible.
My transmission guy had been rebuilding transmissions for 40 years and it baffled him and drove him crazy. He had used other Trans-Go kits and never had a problem. My transmission is shifting perfectly since putting the original valve back in. Good luck and let us know what happens.

 

I talked to pat barret from level 10.He said disconnect the electric kick down.Then see if it does the same thing.Then put a vacuum guage on the modulator.