Have had a whine for about two years now. I think it is getting worse after the output flange got replaced and now added power is probably pushing it further. Proactively searching for PTU pricing and such there are 2 versions of the PTU based on build date. Anyone have a clue what the difference is?
AT4Z-7251-E Transfer Case
TAURUS; 3.5L; W/TURBO; TO 7/16/13
$630.16
DG1Z-7251-D Transfer Case
TAURUS; 3.5L; W/TURBO; FROM 7/16/13 TO 1/17/16
$696.64