Ok My Turn For Advice

[Unity Jon]

my car (1991 corolla gti) has developed a wierd humming/throbbing noise, it's audible at about 30+ mph and sounds like a bearing giving up, i've checked all the bearings and there is no play, i've looked at gearbox oil, CV joints, diff oil and everything seems ok

the noise sort of goes 'whumph whumph whumph' its low pitched and is speed related, if i dip the clutch the noise stays audible so i know its not engine related.

any ideas ? have i missed something obvious ? maybe a bearing in the box but i thought the boxes were almost indestructable

[MyV6Flys]

Could be a tire seperating internally or a flat spot if you hit the brakes hard in the last few days.

[Unity Jon]

Could be a tire seperating internally

that sounds worrying, i've never heard of that before !! anyway to check it out ? i guess if i switch my wheels front for back and the noise 'moves' it could be....

definately no flat spot, i know what that sounds like.

thanks

[MyV6Flys]

Another way to check the bearings, after driving for a few miles. Get out and put your hand down near the center of the wheel. If you feel Heat, try another wheel in the same spot, if it is cold, you may have found your hum/whump sound.

Also while you have your tire in the air to change it. Give it a spin and watch the lines in the tred. They should not appear to move from side to side. I would check the front ones first.

Good luck.