BAMFingOh10

I am looking to get new gears for my non-SC/TC 2010 V6. I have the 7.5 axle and have bought but not installed a T-Lok by FRPP. The 4.10 gears I'm look at will raise my baseline RPMs by 400-500 minimal on the highway, so I know I will need to get my speedometer adjusted.

I was wondering if a CAI/tuner can do this accurately if you have taller gears. I haven’t bought a CAI/tuner yet, but I’m realizing it may be better to get before the new gears. If I go non-TC/SC and get the gears and 7.5 T-Lok and gears installed without a CAI, can the service people of my Ford dealer hook my car up to a machine that does the speedometer modification? If not, will I need to buy a different speedometer gear? Does anyone know if they carry different sizes, or do I need to buy it online?

Joshspony

ok, first of all, if you intend to ever go Forced Injection (TC or SC) you really should upgrade to the bigger rear end. I know that your post said you are non FI, but if you ever plan on it, now is the time to save some money. Put gears in now $$$, replace rear end in future more $$$.

The gears will make your speedo off. A tuner will take care of it. Getting a CAI/tuner at the same time is a good idea. You simply tell the person writting your tune about your gear or rear end swap and they can write the tune accordingly. On a side note, try to get a custom tune instead of a "canned" tune. Custom tunes will be written for your car, a canned tune will just be a close match to what you have.

I have never done this, but I used the search feature on the forum to get this info. Questions are good but so is the search, you may get more info out of the search than an individual question. Here is the link that I just read.
https://mustangforums.com/forum/4-6l...-question.html

BAMFingOh10

Looks like I'll be selling or exchanging the T-Lok. I am just not sure as to how exactly a larger axle will help... but I'll try running a search. Thanks for the advice mate.

Joshspony

you would be getting a larger differencial. currently your have a 7.5" rear end and would want to go to a 8.8". With FI you will put to much strain on the smaller diff and likely break the "teeth" off of the gears inside. Here is a link to wikipedia, look it over and it shows what I mean.

http://en.wikipedia.org/wiki/Differe...hanical_device)

Basically, the bigger rear end can take more abuse. Also, you are getting into expensive territory. Some where along the line you may also want to look into getting an aluminum driveshaft.

The more research you do, the better you will understand how and what you will want to do.

injen07

Just installed my new exhaust, but my next mod will be gears, 4.10's to be exact because a lot of people seem to recommend those more. I found some for $170 at some website, but is that all I need, besides a mechanic. I currently have the Diablo Sport tune, AFE intake, and Flowmaster exhaust installed as well. Will I still feel that difference people talk about if I get the one for my rear (7.5")? I ask because a lot of people in the forum are also suggesting to use the 8.8", but if it's more hastle and is barely a difference, then I would rather go the 7.5, which is what I'm probably going to go with. I'm new to gears, but I heard a lot about them making a dramatic difference in performance. Any help is much appreciated.
Thanks

Nuke

You'll need the tuner to adjust the speedo due to gears and tire size changes. Get a good CAI & tune combo from Brenspeed or Bama or VMP or Tillman. You won't be sorry.

injen07

I currently have the AFE intake and Diablo Sport tune. Yeah, I'm trying to find a mechanic who can adjust the tune and install the gears.

28HopUp

No, you will need to get a bearing kit, and you should also install a limited slip differential (LSD) when the gears go in. Adding 4.10's without LSD would be a mistake. If you are an automatic and don't plan on running drag radials at the track, a rebuilt 7.5" rear should be fine. But if you get more serious then you may wish you found a 8.8" GT take-off rear instead.

injen07

Hmmm...more money to spend. How much did you all spend in total for the whole set-up anyways? The gears are my next mod that I'm thinking on getting put on, so hopefully it goes well and any feedback is much appreciated.
Thanks

asci01

you definitively want to add a T-lock if you're going to the trouble of changing gears, but if you do a lot of highway driving you my not want to go higher than 3.73 do to the high rev of the 4.10