Just a quick question here. My brother has a 1990 GMC Sierra 1500 4-wheel drive, automatic. He put a new engine in it (5.7 TBI) and he said his tranny worked fine for about a month. Now he says its stuck in first gear. He can get it to shift to second if he does it manually but cant get third or fourth. Is there a vacuum module or something that he may have forgot to hook up or does he need to hook a computer up to it and reset the transmission? Maybe its just shot too. I plan on fixing it for him so alittle input would help out. Thank you for your time.
Jun 3, 2007 at 6:50 PM