w140 tranny whine when off the throttle
 

my dad's w140 S280 tranny has just gotten out of the tranny shop.
The planetary gear assembly needed replacing as a bearing inside the assembly disintegrated, (lost reverse first... went home then this grinding sound started)... resulting in a tranny rebuild... plus a new planetary gear set.
Anyway... everything seems to be running smoothly in all gears... except there's this whine when you let off the throttle... once you apply just a tad of throttle the whine disappears... what could be the problem? will be returning the car tomorrow... just wanted the board's advice as i find people here are much more knowledgeable than most shops here in the Philippines.

I had whining coming out the transmission before. It turned out to be front pump bearing surrounding torque converter. Somehow after rebuild it would not have enough play for torque converter and it would whine. I bought used tranny and after 1 week it started leaking and making very loud noise. Took it to a shop, took it off the car and it turned out that same front pump bearing spun inside the pump making too much play. Shop owner personally replaced the bearing with new one and no tranny is perfect. All that info was given to me by shop owner who rebuilds trannies. He doesnt rebuild MB trannies but he said that all transmissions have those front pump bearings and they are one of the main whining noise causes.
You could have something else wrong with your tranny but check the bearing as well. It cost me $2 but took day and a half to take tranny out and partially disassemble it. I did it myself and my car is 92 500sel. Yours should be easier since its inline 6.

Good luck.

thanks for the reply. :) so did yours whine when OFF the throttle? or all the time?