i have an 89 automatic vert. while accelerating a humming almost low pitch horn sound would sound from the rear. while gassing in parked and neutral theres no noise. what could be causing this problem?

 

diff?

 

may be. I just bought my vert. not knowing if the original owner did regular servicing, ill be changing every fluid in the car. doing further research i narrowed it down to the wheel bearing, diff and driveshaft. damn! i know changing the wheel bearing isn't cheap and easy, if anyone know for sure whats causing this problem please let me know. thanks in advance

 

tires?

 

Mostly but not surely i know the sound is coming from the rear drivers side. i know for a fact the driver side rear tire is about 30 out of 100 thread left. The passenger rear tire is new so i'll alternate the two and see if theres still noise. thanks

 

Maybe front diff bushing

 

assuming all of your tires are the same size, try swaping them to the front and if the noise follows then its the tire. I believe a wheel bearing would have a high pitch humming sound

 

Wheel bearings. I did mine last year, fixed the humm sound.

 

my 87 did that to. Im pretty sure it is the diff. mine is leaking really bad and when i changed the fluid only like a half quart of diff oil came out. My diff. whines and i think its due to neglect form the previous owner. Also, my front driver side wheel bearing was bad. Im in the process of replacing that.