Hello everyone!, I have finally decided to switch to a Limited Slip rear end for my 9.75. I have decided on the Eaton unit. I have also decided to switch my gears, (front and rear), to 4.30's. Have 275/70/17 now, but plan on either 285, or 305's next time. I found a very reputable shop to do the swap. All he said is bring him everything needed and they will do it. What all do I need. I know I need the Eaton unit, 4.30 gears for the front and rear, oil for the front and rear. Do I need the installation kits for both? I have heard that since the truck only has 30,000 miles, not to waste the money on the installation kits and bearings. I plan on keeping the truck for at least 100K miles and I want to do it right. Any feedback will be appreciated. Thanks Dan

 

The Eaton is a full carrier locker correct? If so then you'll want an install kit for that, and one for the gears. With 30k on them already it'd be worth it to replace them instead of having to worry about it later.

Now do you have a 4x4 and if you do where did you find gears for a reverse rotation 8.8 IFS axle? I've been looking around for em and appears that they don't make them for the front, only for the 8.8 and 9.75 axles.

 

hi again, the Eaton is a limited slip unit. They are coming out with a electronic locker soon called the ELocker. I'm just getting the limited slip unit. Also most manufactures make the reverse rotation gears. I know Ford motorsport does and I think precision too. I'm sure others like Richmond and US gear do too. Also, what do I need to correct the speedometer?
Dan

 

The speedometer is simply a computer reprogram. I'm planning on changing gears and tires and checked into it. Roughly $70-$100 at a dealer and they'll reprogram the computer.

P.S. Nice truck. Mine is starting to look like yours more and more.

 

Wow, thats quite a bit more than I've heard the dealers doing it for. Last I heard it was around $20 to reset the computer.

 

Dan,
First of all, you won't find anyone that makes 4.30 gears for a 9.75" axle. Your choices in that range are 4.11 or 4.56. The lower the ratio (higher number), the more likely you are to get gear noise. The Eaton differential is a great choice. My understanding is that the Ford Performance Parts SVO 4.11 gears for the 9.75" axle are no longer available. You do need an installation kit for both differentials unless your mechanic has every part that could be needed after a complete teardown and inspection at his disposal. At a minimun, the kit needs a pinion seal, a crush sleeve, pinion shims, a new pinion nut, and differential shims. If any of the bearings need replacement upon removal/inspection, they will need to be replaced along with their matching bearing races. For your 9.75" installation kit, you must order one specifically for 2000 and newer trucks; 1999 and earlier are different. To change the differential, the mechanic will use a puller/press to remove/re-install the differential bearings. You may as well install new ones at this point, especially if he damages them. The differential bearings are not as important when someone does a gear change only when the differential bearings are left alone. The rear pinion bearing is also removed/re-installed with a bearing separator and a puller/or press; once again damage can occur here. It's cheap insurance to install new pinion bearings. Basically, if you're buying a installation kit without bearings, you're counting on the installer to inspect them and not damage them upon re-installation. So, save yourself the headaches and get pinion bearings and differential bearings in your kit if you put in a new differential and gears. The speedometer is not a simple dealer stop. They wouldn't give you coffee and a kick in the *** at a dealership for $20. The dealership can only calibrate the computer with the tire height/gear ratio combinations that were available on your truck. So, if your not using factory tire height/gear ratio combinations, then your out of luck at the dealer. To correct your speedometer to any tire height/gear ratio, you'll need to get your Superchip recalibrated by filling out a worksheet with the proper specifications and sending it to a qualified Superchip dealer.

 

I just installed the Eaton LS in my 8.8 on weds and it is great. I replaced my Powertrax No-slip which was uncomfortable in turns on pavement. I also put in Ford Racing 4.10 gears (which are good quality and quiet) but there may be a problem getting the gears for the 9.75. I got the best price on the locker and the installation kits at Randy's ring and pinion and the best price on the gears at Summit Racing.
I definitely agree with max mitchell, replace all the bearing when doing the install. My bearings were less then a year old but for all the money you are putting out, why chance it for the price of an install kit.