01 Cobra Convertible rear end noise

Sounds exactly like what I felt when my differential clutch packs needed replacement. Do you have to drive over 10 miles for it to occur?

There is a procedure to test the clutch packs out.

bkakers said:

This issue is not the same as the shifting clunking noise that we all have. I have recently noticed a noise/vibration in the rear end when going into a turn on uneven pavement. In other words, if the rear end is going around and the left and right wheel are uneven and have to adjust, it make a strange obvious noise similar to as if there was something heavy in the trunk that is bouncing up and down.

I had all the rear bolts tightened per specs and also the stabilizer bar, but the noise still prevails. Anyone else have this issue?

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I only noticed mine after driving over 10 miles.

Sorry I don't have the procedure handy to give to you. I remember it involves holding one wheel and seeing how much torque resistence there is before the other wheel will spin.

bkakers said:

No, it happens immediately, warm or cold. What is the test? thanks

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One way to see if you need clutch packs is the "one wheel peel" sympton. Just burn out from a stop and see if you have one or two wheel burn marks. If you only have one, then your TractionLock isn't working and you need new clutches. It may be ghetto but it will tell the story.

Clunking may be something else entirely, though. Clutch packs usually don't make much noise when going bad. On the other hand, a bad pinion gear will make noise. You may want to check your rubber bushings on your control arms and other suspension points, including shocks, as when these go bad, you definitely get clunking noises.

Hope it's a bushing issue as replacing rear end internals isn't something to look forward to.

Price1 said:

One way to see if you need clutch packs is the "one wheel peel" sympton. Just burn out from a stop and see if you have one or two wheel burn marks. If you only have one, then your TractionLock isn't working and you need new clutches. It may be ghetto but it will tell the story.

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This will only tell you if your packs are completely worn out or broken. There are other problems that can happen besides a one wheel peel.

Price1 said:

Clunking may be something else entirely, though. Clutch packs usually don't make much noise when going bad. On the other hand, a bad pinion gear will make noise. You may want to check your rubber bushings on your control arms and other suspension points, including shocks, as when these go bad, you definitely get clunking noises.

Hope it's a bushing issue as replacing rear end internals isn't something to look forward to.

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I think you misread what his symptoms are. While pinion bearings or a pinion with a bad runout can cause issues I would expect the issues to show themselves all the time versus only when turning.

BTW, he said it is NOT clunking:

bkakers said:

This issue is not the same as the shifting clunking noise that we all have. I have recently noticed a noise/vibration in the rear end when going into a turn on uneven pavement.

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I stand by my original statement. Have a mechanic test the clutch packs by performing the test I refered to earlier. Think about it, since it only happens while turning it makes sense that the clutch packs could be the problem, that is when you need the clutch packs the most. Hopefully yours is not as bad as my stock unit since I broke some of my spider gears. Of course when Ford serviced under warranty and replaced the clutch packs they left the broken spider gears in.

Here are some pictures of when I took my pumpkin apart, the one on the right is the spider gears that were my stock ones:

http://djtech.org/gallery/view_album.php?set_albumName=99-cobra-pumpkin


How many miles do you have on the rear end? Have you changed the gear oil? You may need to do that and/or put in friction modifier.

Good luck!