3.73 gears

[tim11]

well the thing is that i just got my mustang and im learning about parts for it
i just need help on whats the 8.8 in rear end
and the 3.73gears

[SpectorV]

you have a live rear axle under the back of you car. If you go lay down behind the car in front of the gas tank where the wheels bolt to you will see the rear end it goes all the way across and has a Pumpking round shaped thing in the middle between the tires, the drive shaft bolts to the other side of this, the drive shaft comes from the transmission.

The pumpkin holds the rear end gears, the drive shaft turns the rear end gears and then the axles are turned by the differential which the gears are attatched to. If you have a locking differential both wheels will turn, if not one wheel will turn (if its up in the air on wheel will turn one way and the other the other way) your car stock does not have a locking differenatial.

your stock rear end is a 7.5 inch (measured by the size of the pumpkin i belive) and an 8.8 is the SAME rear end with a larger pumpking and larger rear end gears, thus its stronger.

Your stock gear ratio is 3.27, that the drive shafts turning around one full time compared to the wheels turnning around one full time, thats where those numbers come from. One full turn of the wheels equals 3.27, in your case, rotations of the drive shaft.

I would HIGHLY recommend buying a complete 8.8 rear end and having it PROFESIONALY built with 3.73 or 4.10 ratio gears and a rebuilt differential unit (they have locking units stock) then just bolt it up and keep your 7.5 as spare or sell it for a couple hundred bucks~ The axle shats in either rear end are the same (8.8 rear ends from 99 up mustangs will work in 99 up cars, the 99 up 8.8s are longer than the previous years)

[tim11]

Quote: Originally Posted by SpectorV you have a live rear axle under the back of you car. If you go lay down behind the car in front of the gas tank where the wheels bolt to you will see the rear end it goes all the way across and has a Pumpking round shaped thing in the middle between the tires, the drive shaft bolts to the other side of this, the drive shaft comes from the transmission. The pumpkin holds the rear end gears, the drive shaft turns the rear end gears and then the axles are turned by the differential which the gears are attatched to. If you have a locking differential both wheels will turn, if not one wheel will turn (if its up in the air on wheel will turn one way and the other the other way) your car stock does not have a locking differenatial. your stock rear end is a 7.5 inch (measured by the size of the pumpkin i belive) and an 8.8 is the SAME rear end with a larger pumpking and larger rear end gears, thus its stronger. Your stock gear ratio is 3.27, that the drive shafts turning around one full time compared to the wheels turnning around one full time, thats where those numbers come from. One full turn of the wheels equals 3.27, in your case, rotations of the drive shaft. I would HIGHLY recommend buying a complete 8.8 rear end and having it PROFESIONALY built with 3.73 or 4.10 ratio gears and a rebuilt differential unit (they have locking units stock) then just bolt it up and keep your 7.5 as spare or sell it for a couple hundred bucks~ The axle shats in either rear end are the same (8.8 rear ends from 99 up mustangs will work in 99 up cars, the 99 up 8.8s are longer than the previous years)

thanks for the advice and helping me out with this and how much would it cost to do all this i just want to make sure i don't get ripped off

[SpectorV]

a rear end install job is a very tricky thing. Some places want 800 bucks some 100 bucks....

Some places to horrid jobs some do great jobs. The key it to get an installer who does a very good job, even if you have to pay a bit more. It will be worth it down the road when the rear end does not break and cost you double what you have already paid plus the extra to get it done right as it should have been the first time.

This is why I would just buy a brand new 8.8 rear end (but they are for pre 99 cars as I have seen....)

www.speedconcepts.net i do belive has them.

[Kiljosh]

If you are looking for an installer in your area I'm sure if you posted in your regional subforum on this site someone would help you out.

Just ask stangers around town who did their gears and they should tell you. The trick is to goto a shop that does them all the time, yey still charges not too much.

When I was getting mine installed I had to pay 400 for the install.

[SpectorV]

i would get it in writing that if any whine is heard or issues its under warranty for X miles else they will blame it on your "racing" or tell you its normal and you are out a new set of gears and another install with alot of wasted time (once the gears are worn in wrong might as well start over cuz it usually doesnt get better)