Been driving my 71 Duster with a freshly rebuilt 904 for a year and a half, no issues, shifts great, runs good ext. Today suddenly while i was driving it started making a very loud high pitched howling/whining noise. Every time you touch the gas pedal and give it some throttle it starts to whine, as soon as you let off the gas it slows down and then stops whining almost right away. Other than the extremely obnoxious sound, still shifts and drives perfect with no loss of power ext..... Any idea what could be the cause?
Checked the kickdown, its adjust correctly, Fluid level is good, and fluid is clean and doesn't smell burnt.
Checked the kickdown, its adjust correctly, Fluid level is good, and fluid is clean and doesn't smell burnt.















