I have a 1987 firebird 5-speed v6 recently started making a humming noise that seems to get louder the faster I go. Just replaced both axle seals and axle bearings and new back brakes. The noise is still there. The car drives fine with no problems just the humming sound. Anyone have any ideas of what this could be?

 

wheres it humming from. Front or rear?

 

At first I thought is was coming from the rear but its hard to tell, could be the front.

 

Rear-- Check // change differential gear lube.
Dash area-- Speedo cable may need a bit of lube ( IDK what to use, if that's where its coming from, ** may need** have to remove gauge panel. )
Some one with experience could point you how if its the Speedo cable.

 

check the rear diff to be sure its got gear oil in it.

check the transission for fluid as well
can also be a u joint on the drive shaft going bad

does it only make noise when u are pressing or off the clutch peddle, if so it could be the throw out bearing

if its in the front u could have an accesory pully bearing starting to go and or u could have a wheel bearing starting to go bad

 

thanks for all the advice! differential fluid was just changed, I was thinking it could be a wheel bearing on the front. if it is a wheel bearing is it safe to drive and how long can it be driven like this? thanks

 

if its a wheel bearing it is not safe to drive, eventually the wheel bearing will seize up and lock up the tire or worse it may come off.

if the bearing does seize it usually welds itself to the spindle ruining it. so its alot cheaper to replace it before it fails

iirc the inner/outer wheel bearings set is around 20 bucks

 

Turns out it was bad wheel bearings in the front both sides were bad. Thanks everyone for the advice!