Hello all. Just this morning, my car started making a noise. I'd like to see if anyone could offer suggestions of things to do/check in an effort to diagnose and/or repair. Any assistance would be greatly appreciated.

The car is an '88 744GLE, 169k mi, B230F, AW transmission. The noise starts around 10-15mph as a low moan and increases in pitch with speed. At around 60mph it becomes a high pitched steady tone. At 65-70mph the noise seems go away. The noise happens irregardless of engine speed, whether the transmission is in gear or not, irregardless of transmission gear, whether brakes are applied or not. The emergency brake is working correctly, albeit in need of a cable adjustment.

The car is operating 100% normally aside from this noise. No fluid leaks. Transmission is full of fluid and the fluid is not burnt. At last oil change (165k mi),the brake pads appeared to be 60% remaining all around. Ball joints replaced within last 1500mi. Tires are Michelin Symmetry and less than a year old. The car drives straight and true and does not appear to be out of alignment. Tire wear is perfectly normal. I cannot seem to localize the noise.

Based on all of this, I am thinking it is something wheel, hub, brake, driveline related, but not really sure where to start. Since out of the ordinary noises are rarely a good thing, I would like to see if I can fix whatever this is before it becomes a more serious problem. Any thoughts or suggestions would be greatly appreciated. Thank you.
Landon A. Sheely
VCOA Member
'88 744GLE
'94 855T
'96 965