T 400 No 2-3 Shift After Rebuild

[War Wagon]

My son just rebuilt the T 400 for his Jeep an has run into a problem. We tested the trans on jack stands and it shifted through all the gears fine. On the test drive the 1-2 shift was great but it would never shift to 3rd. We checke vacuum to the modulator (new) and that was good. Test drove it again and if he let off the gas it would go into 3rd. It also would shift to 3rd under full power. He used a Hughes rebuild kit and Trans Go shift kit for the rebuild. We pulled the governer and it checked out OK. He then installed springs that came with the shift kit into the governer to make it a full manual shift trans. The springs hold the fly weights open all the time. We also checked the operation of the kick down switch and it worked. Next we plan to check the cone screens to see if they are clogged up, heard this could be the problem. Any thing else we should check before we pull the trans out. Could a lip seal gotten cut on the install? Reverse works fine also so I am out of ideas.

Thanks for any help,
Jim

[gsmikie]

make sure the kick down solinoid on the valve body is tight

[Ristow]

on my '74,i put the later smaller modulator on,and the i had to put the later modulator valve in as well. they were different lengths.

[Carnuck]

See if teh adjuster screw inside the modulater is cranked in tight. That will do it (or if the hose is off at the intake end or plugged off, that'll do it too. You DON'T want to know!)