I did intend to mention for checking the pinion depth measurement numbers there is a tool set but the least expensive method is to get a piece of precision ground 9 X 1 X .100 stock and a depth mic. Lay the stock across the parting line where the caps go (diagonally, if need be), hold everything together firmly, and measure down to the machined point in the gear and subtract the .1 from the reading. The standard depth setting for a set of gears marked zero is 4.35 inches in a 742 case. Positive numbers etched or stamped into the end of the pinion gear indicate the amount to be added to the depth and negative numbers are subtracted from the depth. Whining on decel usually will pattern toward the outer edge of the gear indicating the pinion isn't setting high enough to the ring gear.