4.0stang

Hey I am thinking about getting 3.73's for my car. I have heard a lot of ppl say to get a t-lok or an LSD. Is this necessary to get? thanks

4.0stang

....?

Arwing

I dont think its necessary

ZZmustang

373s aren't necessary, but neither is a 4.6. You have any real HP and some kind of Posi unit is necessary, unless you like buying one tire.
Few things in life are necessary, Food, air, water, that’s about it. everything else is just something you want. You want a posi unit? get one. Necessary, No. Two black lines on the road as opposed to one, to me that’s necessary
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kopfjager

Since all these 05-07 GTs have LSD from the factory you only need to buy the ring-and-pinion set and the install kit with bearings and crush sleeve. They do make install kits that have axle bearings and the whole nine yards but not necessary on a new car usually. You can buy an aftermarket differential carrier like a Detroit Locker or other limited slip type if you want to upgrade and have another 600 dollars to invest.
I still use the factory Limited Slip carrier with 3.73 and I run slicks at the track and have not had an issue, I hook up very well getting 1.7 or better 60' times.
There are no Mustang GTs that have open carrier (single drive) rear differentials.

redfireshaker06

His is the 6, it might not have the LSD

ZZmustang

I learned something.
All 05-07 have Traction lock or whatever the posi unit is called? Mine is a 06 GT and My daughter and Wife’s cars are SN95 V6 neither of there cars are Posi. The 4.0 must use a 8.8 also?
Huhh!

stangster06

What is LSD?

boomerman

LSD stands for Limited slip differential.

I would put the T-lock in since you already have the rearend apart.
Will save you time and money to do it all at once.
i like the idea that I have both tires being driven now, it helps with the tirespin, keeps the traction control from coming on as much now.
You will be happy that you did the LSD install.

cvz_finezt

the 6's have a 7.5 rear with 3.31 gears and an open diff. so if u get the gears might as well get the posi unit along with it