Error404

I have noticed that when I make a turn I can hear a groaning/moaning sound with a slight bit of grinding coming from the rear end. It's louder if I take my foot off the brake (like going down hill, or on a flat surface) and gets quieter when I push the accelerator. My description of the sound was "like an old creeky metal boat".

It seems to be more noticable when I'm driving slow, probably because I turn the wheel farther when I'm gong slow, when I'm going freeway speeds I don't ever turn the wheel very much. It's louder once the car has been driven for a few miles, but it's still there when the car is cold, just not as loud. Once the car is fully warmed up (or whatever) it's pretty loud, I can hear it over my exhaust and sensibly volumed music.

I had a shop look at the car and they are confident that it's the clutch packs that need to be replaced, and I have no cause to doubt them. I'm wondering if this has happened on any other folks cars before? From asking around a little bit, this noise is apparently a characteristic of our rear-ends, but on a much much softer scale, not really audible under normal circumstances.

Has anyone had this problem before? What exactly causes clutch packs to go bad? I don't know to much about rear-ends.

I recently had 4.10 gears installed with hardly any gear noise at all, and I'm fairly confident that the gears were installed properly (installed by a respected mustang shop), but is there a way the gear install is related to this noise?

dzcues

I just had the same problem & they had to replace the clutch pack in the rear end. Problem solved.

There is a TSB out on the '05s about the problem (ford tsb 05-21-2). To solve the problem, they changed the composite disc from a solid to a segmented disc. Even though my '06 had the upgraded clutch pack, one of the steel discs showed severe chatter on both sides. They test drove my car, ordered the parts & installed them the following week. It is safe, though annoying, to drive the car until your parts are in. FYI, in my case, it happened at the 3500 mile mark. The installation only takes a few hours.

However, you might have a problem getting it covered under warranty since you had the gears replaced. The argument could be made that the installers failed to use the proper rear end lubricant & additives for the posi unit. Then again, they might not even notice the gear change.

Error404

sounds like we had the same exact problem! My car has just under 5k miles.

The new clutch pack, did you have it replaced with the factory spec OEM pack that originally came in the car, or did you have a different/upgraded pack installed?

We tried to see if any dealers would do it under warrenty, but they would not. because the rear-end has already been touched by another shop, but I have no problem paying for the install, that noise is darn anoying. lol

stoon aucoin

clutch packs for sure! had the same problem w/ my 06 gt std. the dealership replaced the clutch packs( and installed 4.10s) and it's all gravy- especially the 4.10s.

Error404

wow, I feel alot better now that other folks have encountered the same problem! I searched around (on this forum, others, and google) and couldn't find anything relating to loud clutch packs, only thing I found was normal gear noises problems.

For you as well, did they use the factory pack when they replaced them? or an aftermarket/upgraded one? Did they mention what caused the loud noises to begin with? I drove my car pretty hard through alot of turns when the car was stock, I'm wondering if maybe that had something to do with it? or if it's just random.

Error404

a bump for the night crew, anyone know how or why the clutch pack got loud like that? seems like it's happened to a few people, is it just bad luck?

BuzzyStang05

Check out Brads thread on rear end groan and 05stangkc's thread on tight posi. I just dumped a bottle of XL-3 into my rear and and no more groaning...

dzcues

The '06 comes with the upgraded clutch pack but it still went bad. They replaced it with the same, upgraded pack that was originally in it. There is no other clutch pack available.

They couldn't say why the original went bad but they were very careful to coat all surfaces on the replacement pack with the proper posi unit additive. It sounds like it's just bad luck if yours goes bad. Maybe whoever assembled the rearend in Flatrock had a bad day.

Buzzystang05 mentions adding XL-3 to the unit but if the clutch plate already has chatter marks on it, the best you're going to do is hide the problem for a while. A damaged part will not get better...it has to be replaced.

No idea what the cost would be if you pay out-of-pocket. On the bright side, the repair only takes a few hours.

Error404

I believe the shop quoted me less than $200 for the parts (and oils/additives I guess?) and a few hours of labor. No biggie. I'll make sure and remind/ask them to make sure they put the additive onto the pack thoroughly. (but they probably already know that)

Firedude

I do not believe the clutch plates are going bad. I read a service bulletin from Ford awhile back stating that they made noise so the replacement was a different clutch pack with different material. Mine has been doing it for quite some time. Still performs good.

Error404

Mine has been doing it for a few months now (It's a weekend car), it's really quite loud once the car gets warmed up, but it still seems to perform well (though I haven't done any burnouts or anything like that). I can't see how something making that much noise wouldn't fail eventually, it's pretty loud.

dzcues

I saw my old clutch plates. One steel plate was bad, showing severe chatter marks worn into both faces, as were the 2 segmented composite plates that mated with it.

Let me try to explain the exact problem: You know how your windshield wipers sometimes "stutter" across your window if it's not wet enough? That's a form of chatter. Now imagine your wipers being made of a more agressive material than rubber...and keeping your wipers on all the time...and the rain never coming down hard enough to eliminate the chatter. Eventually, you will wear a pattern into the glass itself. This is essentially what happens to the clutch plates when you hear the groaning.

If you're hearing the groaning every time you turn, you have permanent damage. It will not go away on its own. It will continue to perform well until it reaches the point of complete failure. If I were the dealer who had to repair the rearend at that point, I would consider the owner guilty of negligence. The groaning noise is a clear sign that something is not right.

I don't mean to sound contentious but your car is telling you there is a problem. Ignoring it won't make it go away. The fact that Ford has a service bulletin about the problem shows that it should be fixed.

Now I'll shut up :-)

Firedude

I do not expect it to go away. I understang what chatter is and can do also. I have a couple cars with posi's that make noise. They have gone many many miles. I am not saying you did not have a problem. I do know that a lot of people who have not had performance cars like these before are complaining about every noise they here. Trans noise, gear noise, clutch noise, injector noise and the list goes on. Some are problems and some are the nature of the beast. Some people are expecting these cars to be as quite as their Crown Vic. Ford is pretty much doing what it takes to make the customer happy. They have replaced many parts that were not bad to get rid of noise.

Error404

Yes, I expect my car to be fairly quiet, because I know plenth of other cars that are quiet with 4.10 gears. I don't mind the slight whine of the gears at all, but this loud grinding sound has got to go should be done by next weekend I think, when the part arrives. My old camaro made noises like crazy! but none of the noises were this darn loud and annoying, haha!

Firedude

Yeah, I would say if your noise is that bad you probably have a problem. Mine and a good percentage of those getting parts thrown at them, probably do not. For the people who do not know the difference or have never torn these things appart and know whats going on inside, the dealer is probably the best option. I worked in the automotive repair business for many years and still have friends working for dealerships as well as privately owned. I do not really trust 80% of the people who will touch my car at a dealer or these places. That is why I do most of my own work. If I take my car in to get something replaced and they keep it for days driving the crap out of it, it is not worth it to me. Yes, there is a good chance someone is driving your car harder and with less regard for it than you ever will. The nicer your car is, the better the chance this will happen. I have seen it many times and even done it myself. The service manager may even be taking his wife to lunch in it. It is always easy to explain all this away claiming you are test driving it and trying to get it to make the same noises. Or driving it hard to make sure it does not do it anymore after the repair. If someone is going to drive the crap out of my car, it is going to be me. Most of the people who will work on your car do not give a dam about it or you. There are exceptions of coarse. I hope everyones car goes to the exception.

06GT

I am noticing this "groan" in my 06 as well, when making somewhat tight turns.

I need to scrape all the tire shreds from the dragstrip off my fenders before I go into the dealer, though.

metroplex

Did your factory clutch discs look like this:


Or this:


Chattering clutches = clutches that need more FM.


The top pic is of the 4700-C carbon fiber clutches, used in the 03-04 Cobra and supposedly factory equipped in the S197 GTs.
The bottom pic is of the 4700-B standard clutches, used for 20+ years in 8.8" T-Loks.