ford c4 tranny help

[jamesjohner]

the tranny is shifting directly into third gear. It will run in first until about 10 mph then go basically into third, sometimes when its cold it will shift into second for a bit but will then go to third Very shortly there after no matter how fast im accelerating and it wont down shift once im up to speed and get on it. If i shift it on the dash it will go into all gears beautifully but if i just leave it in drive is when it screws up. any suggestions?

 

[Reid]

sounds like 2nd gear band is burnt up. rebuild time.

 

[mmcj7]

check the modulator valve. http://www.raceabilene.com/kelly/hotrod/images/trans/c4exp.gif If the vacuum hose is off or its bad it won't shift right. Whats the history of the problem? Did it just start or has it been getting worse for a while?

 

[jamesjohner]

i bought the motor and tranny together and ive had them for about a year and its always done it. it gets worse when its up to operating temp. and it shifts fine if i go through the gears manually no slip no nothing

 

[GubNi]

sounds like the modulator valve. Maybe it's not getting proper vaccume