t bird trans problem

hey guys and gals just got a t birb in the shop for a trans problem shifted out at 45 mph from 1st to 2nd then about 55 mph no shift at all from second nasty stuff in pan so i bought a "used" tranny from a 91 ford that switch out on the exchange deal so it will work right? well its doing the same thing as the old one did any ideas? the t-bird is a 84 v-8 the new tranny came out of a 91 ford car any help will ne greatly appreciated thanks mike in new :banghead: mexico :banghead:

Make sure your TV line (kickdown cable) is adjusted properly. If it is too tight it won't allow the trans to shift properly. Just a thought...

[ ive check it it non adjustable ive even taken it off no change

agree with flew on this but 84 didnt have cable it had solid linkage rod that went from cfi unit to kickdown on side of trans and with no linkage rod hooked up it defaults to passing gear(internal spring loaded ) 91 did have cable so not exact swap i learned this on my 84 5.0 cougar and i would check shift modulator if all else is ok cause the leak tranny fluid internally thru a rubber diaphragm this too will not let trans shift