When it comes to transmissions if it has been broke .. I've broke it. Sure sounds like a input or the 1.76's are gone to me. I've never broke a 1.76 but I have buddies who break them right and left 1.80 is the only way to go.
I've broken oh 6 pumps in 3 yrs it acts nothing like a broken pump IMO(thank god I found a good trans guy now)