Anyone know what would cause the TH400 to NOT shift into 3rd at full throttle? 1-2 is firm but you have to let off the gas to get the 2-3 shift. I'm hoping it's not the clutches/bands...
played with.... was the trans ever played with lately???? first, unplug the wire to the trans, does the trans do anything different?? then try testing the vacuum to the modulator... you should have full vacuum to the modulator. If you do, then get a good used or new one, install it.. any difference???? if not, sorry to say but you may have blown high gear. (clutchers) pull dipstick out, smell fluid.. burnt? dark?? let me know...