Weird Noise

[Blacksnake]

I'm new to this site. I own a 03 Cobra and need help solving the problem of a humming noise coming from the rear of my car when driving. I'm not sure but I think a similar post was placed by 'Blueovalboy' and 'Mk028" chimmed in with the answer. If anyone knows how to solve this problem please help. I've even considered trading the car. This humming soud isn't coming from the tires. I just bought new tires because I thought it might solve the problem. The noise it even louder under load ( when I step on the gas). iI love my car but will trade to escape the noise.:worried:

[BurnTire]

I'm new to this site. I own a 03 Cobra and need help solving the problem of a humming noise coming from the rear of my car when driving. I'm not sure but I think a similar post was placed by 'Blueovalboy' and 'Mk028" chimmed in with the answer. If anyone knows how to solve this problem please help. I've even considered trading the car. This humming soud isn't coming from the tires. I just bought new tires because I thought it might solve the problem. The noise it even louder under load ( when I step on the gas). iI love my car but will trade to escape the noise.:worried:

Does it still have the IRS?

Does it get worse with speed?

[Ethan@S3M]

My 8.8 is making a ''humming" noise too. Dont know if one of the rear pads is rubbing the rotor or a axel bearing is going out. Gets really bad when I turn right.

[AZSonicSnake]

had the same thing in my 98 gt, ended up being a carrier bearing for the diff...

[Blacksnake]

BurnTire,Yes the car still has the IRS. Stock car, no mods yet. Gets worse with speed.

[Blacksnake]

Blueovalboy and Mk028 might have the answer. Anyone know how to erach them?

[BurnTire]

Sounds to me like you have the dreaded vib. It is usually drive shaft or half shaft related. To start I would index and rotate the driveshaft 90 degrees.

[About2Bite]

Does the vibe start at about 70 or so? Or is it always there when driving? If it is constant then I doubt it is the unbalanced drive shaft prob, but if it come around 70-80 then it is more than likely the drive shaft. It is a know problem with these cars.

Josh

[Blacksnake]

No the noise is constant at any speed above 20mph. Thanks for the advice. I'll keep you posted once I learn more.

[5.0Stanger]

Are you the original owner of the car?

If not, I'd think it was something like a bad pinion angle. The 'vib' (I think BurnTire meant vibe) was lessened for me, when I swapped out the stock diff bushings for the Maximum Motorsport aluminum diff bushing set. You can dial in the correct/matching angle to the transmission output shaft. Sure, mine only has the vibration at like 90, but I'm rarely running down the highway at a constant 90. Also, if the rear diff was serviced (oil drained and refilled) for any reason, I'd be thinking that the level may not be where it should be (burnt bearings).

Just my two cents.

[About2Bite]

Like 5.0 said Aluminum bushings should help with any vibes as well, there is a kit you can purchase that also comes with adjustable sway bar end links and the whole kit should also eliminate any wheel hop as well help with the vibe.

You can check and make sure everything is torqued to the correct specs and your alignment is good.

Josh

[Blacksnake]

Thanks for the advice. I'm off to the Blue Oval Office now to have the car checked. Let's hope it 's something simple and cheap.

[Blacksnake]

Well 5.0stanger andAbout2bite were close the the problem. The entire rear will be rebuilt and new gears installed. Ford wanted $1000 just to take it apart and look at it. So I went to the local rearend specialist and after diagnosing the problem, they are going to rebuild the entire rearend ( gears busings and master rebuild kit and labor) for $1100 and have my car back in 2-3 days as oppossed to Ford having it 2-3 days and $1000 just to look at it.