I have a 91 5.0 with an aod. I had it rebuilt about three yrs ago. All of a sudden it stopped shifting any thing i can do. to replace C-4or c-6

 

Two words art carr

 

that's odd as they give a lil warning....you can get a free est. at several transmission place aleast do that...if bad then go with a c-4 2500 stall and good shift kit,deep trans pan and trans cooler and you have years of trouble free operation