How much rearend noise is normal for 08 GT500?

[mikes35]

I have a high mileage convertible, just recently bought it. It has a constant noise coming from the rear, almost like a grinding noise - not a whining noise. I've heard a few folks say the rearends in these cars make noise, but what is normal? Maybe it's louder because I have a vert, but it's quite loud in the cabin. I had the car on a lift and running in gear and with an automotive stethoscope I couldn't pinpoint the source. Any advice? Thanks

 

[GT500RedStripe]

You should check the upper control arm and lowers to see if they are noisier aftermarket versions installed by a previous owner. They can radiate lots of noise into the cabin, especially the upper. Also, if the gears were changed, they may have not been set up right which I've found to be an art.

 

[fmylife]

My '08 vert whines realllllyyyyyy bad but it's because of the FRPP 3.73s. We've tried resetting them several times now with no change so I've got a set of Motive 3.73s to replace them with. Does yours have stock gears? I can't believe how many GT500s have issues with noisy rears...

 

[mikes35]

I'll check the control arms to see if they are aftermarket, I suspect I 'd see a ford stamping on them somewhere if they are original. I'm not sure if it has stock gears, I think so as it didn't appear to be modified in any way when I purchased it. Thanks for the replies

 

[Willie]

I currently own two 2008's.
#1:
Original owner with 60k miles. Original 3.31's. I have spherical rod ended LCA's and they make lots of noise. No other noise detected.
#2:
Second owner. I've put on 9k miles. FRPP 3.73's installed by original owner at a Ford dealership. Absolutely no noise of any kind.

 

[Robert M]

I have a high mileage convertible, just recently bought it. It has a constant noise coming from the rear, almost like a grinding noise - not a whining noise. I've heard a few folks say the rearends in these cars make noise, but what is normal? Maybe it's louder because I have a vert, but it's quite loud in the cabin. I had the car on a lift and running in gear and with an automotive stethoscope I couldn't pinpoint the source. Any advice? Thanks

You said "high mileage" and then "grinding noise". If your GT500 still has the original CF clutch posi. unit, as with any other clutch type posi unit, those clutch discs don't last forever. Once the clutch surface on the friction discs deteriorates, it is metal discs against metal separator plates.

First test............does the posi unit grip well? or does it seem to slip?


R

 

[Robert M]

You said "high mileage" and then "grinding noise". If your GT500 still has the original CF clutch posi. unit, as with any other clutch type posi unit, those clutch discs don't last forever. Once the clutch surface on the friction discs deteriorates, it is metal discs against metal separator plates.

First test............does the posi unit grip well? or does it seem to slip (uneven traction, etc.)?


R

 

[mikes35]

The rearend seems to work fine, I thought about the clutches but I thought it would make noise when turning. My car has 178,000 miles, how long do clutches last?

 

[Robert M]

The rearend seems to work fine, I thought about the clutches but I thought it would make noise when turning. My car has 178,000 miles, how long do clutches last?

It would depend upon the usage and the maint. (fluid change with correct additive) of the axle assy.


R

 

[mikes35]

Unfortunately I don't know what the previous owner did as far as maintenance, the differential cover appears to not have been removed before, it's clean and has a red/orange sealer holding it in place. I thought about taking it off and changing the fluid and additive. But... I purchased this car from a lot that gave me a 3 month, 4500 mile warranty which covers driveline, except wearable parts. I think i'll let the local Ford dealer make the determination, if it's clutches hopefully they will find something else mechanical so that the warranty will cover it. I'm strongly leaning towards clutches as the noise is pretty much uniform throughout the rearend. I also have a squeak in the passenger side rear when I take off, I'll check the control arms as suggested above, makes sense they could be the likely culprit.

 

[Robert M]

Unfortunately I don't know what the previous owner did as far as maintenance, the differential cover appears to not have been removed before, it's clean and has a red/orange sealer holding it in place. I thought about taking it off and changing the fluid and additive. But... I purchased this car from a lot that gave me a 3 month, 4500 mile warranty which covers driveline, except wearable parts. I think i'll let the local Ford dealer make the determination, if it's clutches hopefully they will find something else mechanical so that the warranty will cover it. I'm strongly leaning towards clutches as the noise is pretty much uniform throughout the rearend. I also have a squeak in the passenger side rear when I take off, I'll check the control arms as suggested above, makes sense they could be the likely culprit.

Wheel bearings can also make a grinding sound when they roll against a worn axle surface.



R