It’s no secret that the gears in the rearend of your car have a huge effect on its performance. If you have a gear that is numerically too high, the long distance driving is hampered. Add a gear that is numerically too low, and while long distance trips will be fuel efficient, you can forget about playing at a redlight. We know that many of you late-model Mustang guys have been waiting for US Gear to make different gear ratios available so you can upgrade your pony, and finally, the wait is over.

When the 2015 Mustang was released, Ford made some changes to the 8.8-inch differential. For starters, the gear face cut has been changed, and the bearings are now larger. The housing has not changed, but the differential is now much stronger.


We talked Bob Angliss of US Gear, and according to him, “Ford offers a 3.73 gear, so what we’ve done is also offer a 3.73 ratio – because customers asked, and we’ve also got 3.91 and 4.11 gears.”

The gears are made from 8620 steel, and are vibratory polished to remove any tool marks, and to give an extremely smooth surface finish. The advantages of this process, according to Angliss, are that you no longer have to perform a break-in on the gear, it reduces friction, and it increases durability, because you’ve taken the stress risers and impurities out of the finish. It also reduces the lubrication requirements and helps the gear lube last longer.

US Gear is also making available, complete bearing and installation kits for these and many other popular rearends.

So when you’re ready to upgrade your rearend, check out US Gear as they have everything you will need.