hi all. i have a 96 tahoe, 2 dr. its 4x4 and has a 3 inch body lift. its my frist chevy truck, and its top notch besides the tranny issue. now ive checked the fluid and its all good. i have a gm tech2 scanner at my work and scanned it and it has no codes whatsoever for anything. ive scanned it with genesis, snap on solus, and a launch scanner as wel and i have no dtcs set and beginning to wonder if im in for a rebuild soon. now the main problem: i crank it up, shift from park to reverese and it makes a noise like you just hit the driveshaft with a hammer..same thing for reverse to drive and so forth. also note that while driving it that if i take my foot off the gas, and tap the gas again it makes the noise again....i have not removed the pan or changed the fluid yet in it, but most likely will do so this weekend. but its just got me stumped and if anyone has had this problem before id like to know a solution before i remove it and tear in to it...thanks.