Here we go again. So, I have had trouble with the transmission in my Suburban for a while. I have made a few posts about this thing. So, I have taken the 700r4's from my 86 GMC Burb, and an 88 Caprice, swapped tail shafts out, and put the one back into my Burb. I have had trouble with the TV cable, so today I put a brand new one in, and set it. The slipping went away, but it will not shift into third, drive. any ideas as to what may be wrong?