GTP drive train help??

[Blk&BluGTP]

2000 grand prix gtp 3.8 S/C 125k miles

driving home other day on highway went up hill and heard a loud bang/pop sound under front end, since this was only a mile from home i got home not noticing to many issues. took car to work next day and noticed that as you drive it sounds almost as if a shaft is spinning off center and at a certain point in rotation it is rubbing or hitting something and makes a noise, also at highway speed it occurs fast enoufh that it is like a constant womp womp womp sound, turn to one side it goes away turn to the other and it gets louder for constant speed. there is no play in the suspension steering is tight it is something in the drive line
luckily at work we have an auto shop so i put it on the lift just to check for obvious damage nothing looks out of place the cv boots are solid not leaking or torn or damaged, sway bar and all other bushings are good, it seems like internal CV joint damage or bad axle and hopefully not something internal to transaxle??
Any help would be appreciated as i prefer to drive my car to work and now i have it parked till i get some ideas.

[GTP Dad]

I would pull the Front tires and check the bearings. Because it goes away when you turn it to one side it sounds like one of the bearings has failed. Also bearings will also cause a noise at speed. Since you checked everything else I would check both front bearings to start. You may also want to check the brake calipers, pads and rotors while you have the tires off.

[Blk&BluGTP]

Thanks for the quick response

The bearings/wheel hubs have both been replaced recently, the brakes and rotors are good as well. it is a strange sound that ive never heard before when the hubs were bad and i know the pads and rotors are good..

not sure if this helps any but the car has been having a pretty extreme vibration feeling when stopped at lights and stop signs for a while, put it in neutral and it goes away. That has been happening now for almost as long as i remember. the two upper wishbone mounts were replaced a few years ago with solid poly mounts. is it possible a lower mount finally broke or something?

[HotZ28]

Check to engine/trans mounts! Start the engine and put it in gear (with brakes applied) and bring the rpm up to 1500, if the motor twist & lifts more than 1/2 in you have a mount problem.

[BNaylor]

Originally Posted by HotZ28

Check to engine/trans mounts! Start the engine and put it in gear (with brakes applied) and bring the rpm up to 1500, if the motor twist & lifts more than 1/2 in you have a mount problem.

Not a bad suggestion Bo, however, there will most likely be an issue testing for bad lower motor/transaxle mounts that way on "W" body cars. The two upper dog bone engine mounts will preclude that type of testing so it may not reveal anything. Needless to say when the lower mounts are suspected it is best to closely inspect them. You may see the pieces of the rubber insulator starting to deteriorate or break away. But in most cases you will have to remove the lower mounts and then see if the rubber insulator has split in half which is what most lower mounts do when they go bad.