I've got about 73,000 miles on my '02 GT (bought it new back in '02) and decided to take it to a local 1/8 mile strip recently for the first time. After my first run, another Mustang owner came up to me and told me there's something wrong with my differential because when I did the burnout, only 1 of my rear tires was spinning. I'm not very familiar with the workings of my car's differential, but when I light up the rear tires, shouldn't both of them spin? I'm not sure which tire was spinning, at the time I didn't think to ask, but does this sound like there's something wrong with the differential? The only thing I've really noticed that may also indicate this is that when I make a tight slow-speed turn (like turning into a parking space) I can hear a clicking noise coming from the rear end (doesn't happen all the time though, and it's not very loud). Any help or advice you guys can offer is greatly appreciated.

p.s. everything in the rear end is stock, although if i have to replace the differential i will probably go to a 3.73 or 4.10 gear

 

i believe the GTs have posi... they should both spin if the posi is in good shape...

posi works because there are clutches tensioned with a spring within the rear end... if the clutch plates start to wear, or the spring wears you might need to replace them...

if its a 02 i dont believe you should be having a problem unless you light them up a lot...

another thing that might happen is one tire had more traction then the other which caused the posi to slip causing the other tire to be the only tire to spin... if that is the case, your posi is a little weak...

it wont be a problem driving it like that... your just not transfering all your power to the road when you are ripping into it

 

yeah i don't drive the car very hard at all... i get on it every now and then, but i don't rag on it like some people might, so it's in real good shape compared to other '02s i've seen. there's a spot down the road out of town with some twisties that i like to hit up on my sportbike, so i took my car out there this morning and after letting the tires get warmed up i went through the twisties at a pretty quick pace, and whenever i made a left-hand turn and came out under full throttle, it felt fine. but when i made a right-hand turn under full throttle, the back end gets REAL loose and i have to let off. it feels like only the RR wheel is under power, and when weight transfers off the RR then it just breaks traction. it doesn't do this when i makea left-hand turn though (when most of the weight is planted on the RR tire). just for good measure i stopped and did a burnout and there was only one tread mark on the road from the RR tire.

does anyone have any suggestions for a good replacement differential? there's a possibility that i will do an engine rebuild sometime in the next 3 or 4 years, i plan on building a stroker with some hotter cams, ported heads, and possibly a supercharger, so i'm not sure if a stock-replacement differential would be up to the task of handling that kind of power.

 

the stock differential shouldn't have a problem... but id suggest putting in rear end gears when you do replace it...

 

sounds like you need to replace the clutch pack at the least or if you drive it hard you could of destroyed the spider gears

drivetrainspecialists.com has rebuild kits or if you want you could upgrade to a detroit true trac and not worry about it, i would also recomend atleast 4.10s gears if not 4.30s

 

i dont see how one tire not spinning would mean he needs a clutch pack.. if the rear end is getting power, it should transfer it equally, unless the differential is going out...

you'd know if your clutch was going out anyway..

ive got 4.10s

 

ok one more question... i called the local Ford service departments and they acted like they had no clue what i was talking about... i'm looking at differentials for my car and i see some are 28 spline and some are 31 spline, but i'm not sure whether my axles are 28 or 31. does anyone know which axles come stock in the '02 GT?

 

i think he meant the clutch pack inside the differential. if i'm not mistaken, i believe that the limited slip differential has clutch packs similar to those of an automatic transmission.