WuTimeUT

Well I can't believe it, but after having the TSB stuff done at my local Ford Dealership..... the axle groan is back. Its only been about 4 months, same old sh*t and once again its driving me crazy..... WTF.... I can't believe its back

Hatchman

Add another bottle of friction modifier and do some figure 8's.

Error404

can you describe the 'groan'? Mine was sounding like an old creaky metal boat (scraping, moaning, and jittery groaning when I would make turns, the sharper the turn, the louder the noise). It turned out that it was my clutch packs in the rear end. Had them replaced, and the noise is completely gone.

RadBOSS

When you are turning a corner, the clutches are designed to slip, the more power you add going thru the corner, they slip less. If enough torque is applied they basically can lock up, hence give you drive torque to both of the rear wheels. Hence the term traction loc. The traction loc on my 69 BOSS groans too, Its a fact of life.

Error404

a fact of life? when I replaced mine (with the same factory spec part), the noise went away. I haven't ever heard another car do this before either, new or old. not as loud as mine anyway, my was really loud.

Hatchman

Are you sure you didn't get the new clutch pack with less material on it? Then again, some clutch packs groan, some don't. Most are fixed by adding some friction modifier.

http://forums.bradbarnett.net/showth...rear+end+groan

RadBOSS

You just want to be careful you don't get carried away with that additive, too much will make the traction lock less effective. So there is a point of diminishing returns.

If the groan is that annoying, the alternative is to put in a std diff, but then you loose the benefit of the other.

I have had my 9" limited slip apart a few times over the years. I have not seen the workings of the 05 one, but for the 9" there are some critical stackup dimensions to maintain by using the correct shim, so I would expect similar adjstment on the 05, as its not only the clutch disks that wear. Get it wrong and it won't be happy.

Error404

as far as I know it was the same part number. Mine started making the loud sounds a while after I had my gears installed, if it was related to the install or not, I can't say. But the replacement has held up just fine, by the same shop.

34124231user

I recently added the small bottle of Ford Friction Modifier, and the groaning during tight turns has gone away. I have not experienced any changes with my limited slip diff since adding the modifier- it works great now, and no wierd noises. If the goran returns, I will bring the car into the dealer.

traffic142

My only problem was when I get on it in a turn, my ABS/Traction lights come on. When I turn the key off and restart the car it goes away.

zipperhead

I also have recently started to hear this same noise. I have recently replaced my stock 331 with 373 gears. What is the down side of just putting up with the noise? The noise in my car is very intermitted but I suspect it can reduced or eliminated with more friction modifier

WuTimeUT

to be honest the noise is annoying but if theres no mech hurting then I can deal with it

sodaman

If your clutch paks are set up right, you will not hear any groan. If it does the adjustments are not made properly. Should not have to add any modifiers, take it back to the dealer. I did no noise.

profitline

I had the groan on my '06 GT, took it in to Mossy Ford and two weeks later after having the clutch packs replaced, what do you know, groan is back and louder than ever. This will be cool taking the car in every two weeks to have the differential ripped to pieces!

Firedude

Mine has been doing it for the last 8000 miles. I would not and don't, worry about it. Just drive it.

mvon919

HEy, I'm about to take my car to the dealer tomorrow to get that groan fixed, but after reading these posts that it's more likely to come back I just might forget it... gotta take it in though to get rid of that clunking noise in the front.

WuTimeUT

Ya I actually took it in the first time cause I had a problem with the passenger side airbag sensor, so I just got the groan fixed too. Now idk if I can handle not having my car for that long again....

mvon919

I think I'll suggest them adding some FM to see if it helps. Reading from posts the groan is more likely to come back again and mine is not even bad. Apart from some posts, I believe that if the clutch discs aren't "really broken" if FM can get rid of groaning. If they really are worn out (cause of grind) no FM would fix it.

metroplex

A friend of mine who likes old Chevys said that it is kind of a hit or miss... He had a 70s Camaro that had a very noisy rear end but it worked fine at the track (2 wheel burnouts). He had a 80s Camaro with a quiet rear end and it worked fine as well.

Since no one here actually checked to see if the Dealership replaced the clutch packs (and asking for the original parts - which btw, you should ALWAYS do when dealing with a dealership...) it could very well be the nature of the carbon fiber clutches Ford is supposedly using on the S-197 GTs.

The 03-04 Cobras are supposed to use the same carbon fiber clutches. Has anyone consulted with or listened to the rear end on a 03-04 Cobra to see if they have the same problem? Someone, somewhere must have grenaded a 03-04 Cobra rear end and tore it apart for a rebuild. They would know if the carbon fiber clutches were used in their car and if it made noises when turning.

34124231user

Update on using friction modifier:

I'm at 5800 miles now- over 4000 since adding one bottle of Ford friction modifier. Differential sounds just fine- no weird noises, and I even took it drag racing about 1000 miles ago. All is good so far.