First off, I have new michelin sport tires, so I haven't been burning them lately, so that is why i just noticed.

I recently had 4.10's put in, and some annoyances with the sound, which I will explain in a second, but recently, I don't know if it is in my head or not, but it just seems to feel more sluggish in 1st when I don't try to spin. The best way to describe it is that it feels lean, and then finally kicks in at around 4000 RPM.
I thought maybe I wasn't getting on it enough, so I let my tires slip a bit on the launch and noticed afterwards that the burn was uneven. To rule out the road conditions and shape, I moved to a nice flat spot and tried again. Sure enough, there is barely a mark from the passenger side, while my side left a lot of rubber.

Thoughts guys?

 

Is there friction modifier in the rear end?
Did the 4.10 installer put it in there?
I would suspect a worn out T-Loc.

 

Thanks for the reply. I took it back and had them add friction moddifier. They said that they did not do it previously because they used full synthetic oil.
The sound got worse over time. It does it on acceleration but mainly if I feather the pedal; just barely enough pressure, and if held, it makes a loud buzz saw noise. It does it in every gear, but typically gets more full sounding in higher gears, but also increases pitch with the revolutions.
In first gear though, it is very high pitched and almost has a supercharger wine sound to it.

Honestly, I don't do many burnouts. I did my first year, but not really anymore. Do you think the T-Loc would be under warranty?
Also, what is a T-loc and does it come stock?

 

One thing I can saw is go to a differrent installer. One with experience. That's why it's whining and that's why they didn't put the friction modifier in it.

 

So is there an easy way to tell if the differential is messed up? I don't really want to have to go to a dealer, do a burnout, and then point and say "see?".

 

Friction modifier is not gonna fix it. It may make it worse. It is needed to keep the clutches quiet, it makes them slip on each other easier. Probably needs new clutches installed, you can upgrade to carbon fiber.

http://www.buyfordracing.com/shop/pr...=609cPath=3_37

 

what tuner did you use for the 4.10s bama,brenspeed or someone else.

 

I have the SCT X3. That leads me to something else, so sorry it is off topic. I don't know if the SCT removed my rev limiter. I don't want it removed, but I think it is.


Thanks for the link. I am new to all this, so please help me understand.
The parts you linked me to states, "Fits all 8.8" Traction-Lok differentials"
Is that what our mustangs have? All I did was have a 4.10 ring gear and pinion put in.

I am just not sure what approach to take on this yet. I don't take it to the track, but I still get some use out of it.
I don't know if the friction modifier could be making this slip, or if I should go straight to the dealer, and try to have this replaced under warranty. (crazy idea?)
Not sure, because when I bought this car, they told me that it is meant to be driven like we want to, and if I do burn up the clutch, they will replace it. I don't mean to sound like an idiot here...I am just shocked that this early in the game, the car is having issues like this.

 

funny to see somebody else talking about this, because last week i went to the drags, and after i got back, the next morning, i noticed there was more tire rubber on the right side quater panel bottom area and in the wheel well than there was on the left side. i am installing 4:10's monday, so we will see what happens after that. new fluid/friction modifier from the dealer, and professional install, and i will have a look at the t-lock unit while its out.

 

sorry but is not off topic.i ask because my car used to do the same after 4.10s and c&l intake install.after talking to doug at bama and going over my file he found out that half of my transmission was set for 4.10 and the other half wasent,or something like that. this cause one tire to spin faster=burning more rubber than the other.now about the noise coming from the gears is do to a bad install and friction modifier is a most.i have read that the only gear oil that dont need the friction is royal purple but dont quote me on that.