New T400 Rebuild will not Shift to 3rd

[jwillettgn]

My son just rebuilt his T400 with a Hughes rebuild kit and a Trans Go shift kit. Up on jack stands it shifts through the gears fine but on the road it will not shift to 3rd unless you let off of it or stand on it. We check vacuum to the modulator valve and the governor itself. He even installed the Trans Go springs in the governor to hold the weights out for full manual operation and that did not help. The kick down switch was also checked. Heard something about a screen that could clog up and cause this But have not checked that yet. Any way a lip seal could of got messed up to cause this, Reverse works fine by the way. He has a 2500 rpm converter and the trans is behind a 5.3 we are playing with. Trying to work out the bugs before the turbo goes on.

Thanks,
Jim


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[jwillettgn]

Drove it to the muffler shop yesterday to get the exhaust put on and could get it to go into 3rd at higher speeds. It still should go to 3rd any time the shifter is put into 3rd being it set up now for manual shifts. It will start off in 2nd if the shifter is put into 2nd. Hoping we don't have to pull the trans out but will do what we got to do. We are running this engine and trans in a test mule for now. When the engine goes into the GN we have one of Chris's trans sitting here ready to go.

Jim


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[Chuck Leeper]

NE help??
http://67-72chevytrucks.com/vboard/showthread.php?t=250306

 

[jwillettgn]

Thanks Chuck, I have been looking at that site and my search missed that thread somehow.

Jim

 

[Chuck Leeper]

I think I still have a manual on T400 t/s...I'll look and see if I can find it.....