Ok... this is it, my car has 5k miles its a GT Manual transmission.

1. The car makes kind of a squealing noise when I make a slow U turn, seems to be coming from the diff.
2. The Steering squeaks when I move it, even with the car off you can hear the squeal.
3. At 40 to 60 mph I can hear the rear diff humming.
4. 1st and 2nd gear are noisy when they are engaged.

The car does have Mods:

- 20 Inch rims with 275/35 tires all around.
- 1 inch shorter springs in the rear.

Can this problems be fixed outside the dealer? because the only dealer I have near me is very famous for delivering cars worst than they arrived.

And do you think that the mods that I have done have contribuited to this problems. They are recent and did not happen when the mods were done.

Thanks in advance guys.

 

The rear diff. noise is well documented, there is a TSB for it. Many people have tried adding some XL-3 Friction modifier to the rear end and it has worked for everyone that I know of. It is available at your dealer for about $6. If you want to have the dealer fix it however, they will put a new clutch pack in the rear end. My thoughts are the dealer has a good chance of messing up more than they fix. I used the XL-3 about 20K miles ago, no groan, no problems, limited slip still works great!

 

So let me get this right the XL-3 Friction modifier will make the diff quieter AND will eliminate the squeal when doing slow u-turns?

And If so how much do you need and do you just pour it in the filling hole of the diff or you have to drain it and use the friction modifier only?

Thanks for your response Edge.

 

It will eliminate the "howl" you get when making a sharp low speed turn. I don't know if it will get rid of the noise you hear at 40-60mph, but it could. It's worth a try in my opinion. To add it, just put the whole bottle (it's only about 4oz) in the rear diff by opening the rear fill hole. As long as fluid doesn't start coming out of the hole it is not too full and you don't have to remove any fluid. Easy fix, took me about 10 minutes, mostly because the drain plug was so tight and I couldn't find a socket wrench big enough to get the proper torque to remove it.

 

You have a warrenty on the car, so your best bet is to find a dealer you can trust and take it in for repairs

 

OK thanks Edge, I will try that and see if it works. I don't want to take it to the dealer because I heard chances are they will mess the diff even more.

Ill keep you updated.

 

Well I just added the XL-3 fluid... took the car to an empty parking lot to make some circles with the steering wheel turned all the way... and guess what?
It's gone I couldn't have the car make the noise, not even once.

Ill keep you guys posted in case the scenario changes.

Thanx a lot Edge!

I just need to fix 2, 3 and 4? any comments on those?

 

No 3, is most likely a poor set up of the ring and pinion gear. It is going to probably require rear end rebuild with new gears and associated parts. This problem is common and pretty well documented on the forums. The 2005 I briefly owned made the noise on light acceleration between 40-60. Some make the noise on deceleration. I don't know why Ford's supplier can't be more consistent on their set ups. You may have to be persistent to get it repaired and hopefully your dealership has a good tech to perform the job.

As far as No 4 goes, it may be normal for the manual transmission. There are a lot of complaints about the 5-speed in the GT's. I'd drive another one, and see if it is any better or worse than yours.

Good luck.

 

Thanks Lodom, well the noise isn't very loud if I turn the radio on I can't even hear it and much less with the windows down... Is some rear diff noise normal or there shouldn't be any at all?

 

1st and 2nd gear normally make a little whine, sometimes a little growl noise. As long as it isn't loud, or sounds like it is grinding, that is pretty normal for these transmissions.

 

i remember when i test drove an 05 i could hear the gears hum at low speeds and that cause it was an auto, but i guess it is a common problem with the 05 but my 06 does not have the problem

 

It is possible to get a quiet rear set up, and I would have had mine fixed, if I'd of kept the car. My 99 was almost dead silent. The rear diff in the S197 is almost the same as the previous models, with the exception of the 31 spline axles, and it can be properly set up.

I realize you can turn up the radio and cover up most of the noise, but a big part of owning the GT is the wonderful sound of the engine and the exhaust. When you do get it repaired, just take it easy on it for a while before running it hard to give the parts time to break in.

 

Congrats Lodom, 1000 posts! just noticed it, sorry back to topic now!

 

Just seeing the number of people here who have fixed the low speed differential groan using 2-4 oz of XL-3 makes me wonder if the factory ever filled the cases with XL-3?

 

That's what I've always wondered too 'plex- you could be right.

Ford: "hum..... if we don't add the XL3 we can save $3 for every Mustang we make........" lol

I had the same problem, put XL3 in sometime last spring, and have absolutely no noise since that day; I've put probably 6000 miles on the car since then.

 

Thanks! It took me almost 3 years to get there.

There is a fine balance of how much additive vs. fluid you use. If you add too much, you loose some of the effectiveness of the limited slip by inducing more slip. I thought Ford fixed the problem with the redesigned clutch pack, but I guess they didn't get it 100%. I do recall that some people have loosened up their clutches with out adding more additive, by just making hard turns in a parking lot. You'd just have to find a lot without the roaming rental security.

 

There are only 2 types of clutches available from Ford: regular 86-02 style, and the 03-04 Cobra style (Carbon fiber).

The price for the regular style is $50-$60 while the 03-04 Cobra style is $90+. Rumor has it that all 05-up GTs got the Cobra style clutches.

They are easy to tell apart:
Cobra style M-4700-C
http://www.fordracingparts.com/parts...tKeyField=6942


Regular style:
M-4700-B
http://www.fordracingparts.com/parts...tKeyField=5105

 

What if fluid does come out - how much should be removed?

 

About 4 oz worth of gear oil. See if you can use a turkey baster + vacuum hose to suck out about 4 oz worth of gear oil. Add 2-4 oz of the XL-3 friction modifier and see if the low-speed groaning goes away. Try to do low-speed figure 8's in a parking lot.

 

Anyone got pictures of where this fill hole is located at on the rear diff?