First thing in the morning when the vehicle is cold, and after I press on the brake once it makes a whoom..whoom sound coming from the RR wheel area. Will go away once vehicle is driven more than 1/4 mile. This is on my GSLSE and my '81 GSL did this also but over time it got worse and it did it practicly everytime I went around a turn and pressed on the brake. Since this has happened with 2 of my FB's, I would guess that others have experienced this too...Whats going on?????

 

Bearings are going bad.

May also want to check that the wheel lug nuts are on good and tight.

 

can someone else concur before I see how much they are

 

Could be that the brakes are not "releasing" after use like they should... Does the sound go away while you are lightly riding the brakes?

 

ya something like that. happens loudly when cold when first pressing on brakes then after I release its still there but rotationally..whoom whoom whoom. Since this is the 2nd car this is happening to...i thought that this was common.

 

Remove the caliper and clean/lube the slide pins. If they get gummed up, then they have trouble sliding back away from the rotor when released.

 

also your rotors are warped if it goes ..whoom whoom whoom ... like you said .

 

thats one possiblility. Thing is I just put on cross drilled slotted rotors about 5000 miles ago and it only happens intermittently especially when the car has sat for a while. I KNOW I lubed the slides very well. We all know that fronts warp faster than the rear. I have NO pulsation in the pedal or in the vehicle when I apply the brakes.

What also about bent axle shaft being bent?

 

It may be bearings, a loose brake component, bent axle or bent wheel. You need to narrow it down one by one through elimination.

Do the easiest first, swap the wheels front to back and see if it follows the wheels. Then move on to the brakes. Go over them again since you just did work on them something may be loose. A bent axle can be found by putting the rear up on jack stands, pull the wheels and start it up in first gear and let the hubs spin. Take out a marker and hold it steady and draw on the hub. If it doesn't draw a perfect circle centered on the hub then an axle issue may be present.

Bearings could also cause some wobble and possibly the noise as well.

I'm betting its a bearing issue if you sure the brakes are ok. Bending the axle requires hitting some hard like a curb with the wheels.

 

If it only does it after sitting for a few days, it may be as simple as a light rust coating building up on the rotors while parked. Particularly true if it goes away quickly and does not come back when driven regularly.

 

nah...after sitting for 4 hours or more. its my daily so it is driven regularly. rust buildup isn't that loud and only on that wheel.

 

i like this idea...ill go with it..bearings make sense

 

It's a wheel bearing. I had the same problem and I decided to change both axle bearings.

Buy new ones, get axles pulled out and take them to a machine shop to remove the old ones and press in the new ones....

 

I agree with Kentetsu, also do you use your parking brake, if so that may be the cause of the binding issue if they don't release properly, but then they could ease away after being driven and heated up a little.

 

when i get to about 50kmph i get a loud humming noise with vibration, this is the wheel bearings, am i right? how much do new wheel bearings cost and how many do i need?

 

snakey , your vibration may be coming from bad u-joints in your driveshaft.

 

uh oh! that could get costly! i guess ill know after i replace the bearings

 

check out this thread about replacing u-joints. it only cost me $99.00 total.

https://www.rx7club.com/2nd-generation-specific-1986-1992-17/replacement-u-joints-factory-driveshafts-i-have-them-83551/

 

is this vibration/humming a sure sign of bad u-joints?