bcc333

Anyone have any actual experience with an AUTOMATIC TRANSMISSION and 3.73 v. 4.10 rear ends.

what is your opinion.

do you have any before and after 1/4 mi measured times?

if you had it to do all over, which gear would you go with and why?

notice any difference in mpg cost?

i have read the 4.10 threads but get a little lost in the 5 spd manual v. 5 speed (OD) automatic.

Thanks

SmokeYoV8

A WHILE BACK I RACED A GUY WITH A FEW BOLT ONS AND 410'S IN HIS AUTO 2002 GT.....IT MOVED SO FAST FROM A STOP THAT I GOT BLOWN AWAY TILL ABOUT 95 MPH WHEN I COUGHT UP TO HIM....BUT FROM A ROLL 410'S SEEMED LIKE HIS CAR WAS STANDING STILL AS I WAS 5 BUSSES AHEAD...I PERSONALLY HAVE NO EXPERIENCE WITH GEARS BUT FROM WHAT IVE SEEN ON HIS CAR IT WORKS VERY WELL IN THE 0-60...U HAVE TO ASK URSELF WHAT U WANT TO DO WITH THE CAR AND DECIDE WHICH GEARS U WANT I GUESS. HOPE THIS HELPS

drbobvs

You can't really compare 2002 w/2005 since there are different stock gears. I went withthe 3.73 in my auto and am very pleased. I think 4.10's in the auto is a bit of a stretch but there are others here that are happy w/ them. I'm not the kind of person who likes driving on the highway hearing thir engine revving so i went w the 373s.

As far as times, there are people here on the forum who dropped 3/10 in he qtr w/ 3.73 in their auto. However 3/10 is really a blink of an eye and that's not why you should switch unless racing is important to you. What you really get in changing gears is the SOP feel around town, merging, and jockeying in traffic. And in this regard it is VERY noticable. The usual 20-50 mph around town stuff is alot more satisfying, and it makes my car feel alot more lively. Just my 2c.

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dkano

I have the Motive 3.90 gears on my auto right now, don't recommend those exact gears unless you've got a very good installer that can guarantee to install them and not have them make any noise. I do like how the car pulls with them though (just hate the noise they make when going over 50MPH). I couldn't see myself going down to 3.73, so I ordered the Ford 4.10s two days ago. I'll let you know how they compare once they're installed. Plan on going to the track with them about a week or two weeks after they're installed too.

ren274u

I got 3.73 they gave me at least a tenth off my et only went to the track once after, im going back tommorow so ill see if i can do any better

FredTT

I bought 3.73 and am having them put in on Sat. From what i've been told, putting 3.73s in an auto is the same as putting 4.10 in a standard. In fact, I think the auto will be even geared better. The advantage with going to 4.10 over 3.73 in a auto is VERY small and its not worth the gas mileage that you will lose.

~Fred

757GT

I have 3.73s in my auto '05 GT. I dropped almost 3 tenths of a second off my et going from the 3.31s to the 3.73s. I ran 13.59 before gears and 13.33 after. I also get 25mpg on the highway with the 3.73s.

spyder7724

same here i dropped .3 second with 3.73's. as far as noise i talked to the techs at ford racing and they said that unless you use the new style frpp 3.73 gears you will almost definitely have noise from the differential. something about tooth counts and the way they need to be lapped during the manufacturing process. he told me that 4.10's aren't quite as bad but still(of course recommended frpp gears since they have a new manufacturing routine to prevent such issues. i'm getting rid of my 3.73's and switching to 4.30's or 4.56's in my quest for N/A 11 second times. the FRPP tech thought they would help my combination and could possibly be worth an additional .1-.2 seconds in my car.

JPS51830

I have the 3.73's in mine and love the way she pulls, and did not see any drop in my mileage on the highway. Not sure around town, but I don't keep track there. Can't tell you what the track times will be I haven't been able to get her to a track yet.

757GT

My noise is no longer. I have a new set of Precisions. My shop installed them when the whine on my first gear set got out of hand. They used a $1000 backlash tool and did it all for free. I have no noise now.