If you’re running an aftermarket gear case assembly in your race or muscle car, there’s a fairly good chance that it has a ring and pinion from longtime manufacturer US Gear in it.

The once-family-owned operation founded in 1963 is now a division of AxleTech International, headquartered in Chicago, Illinois, and provides gears to both the OEM and the aftermarket, with a long history in the high performance realm. And just as their products were more than half a century ago, every gear that US Gear produces is manufactured 100 percent in the United States, from casting to the finished product.

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US Gear began in the aftermarket, building Dana and Rockwell axles, Eaton transmissions and transfer cases — gears, shafts, and all forms of driveline parts. In the late 1970s and early 1980s, the company shifted into light-duty automotive gears of OEM quality with higher and tighter tolerances. Today, after being acquired by AxleTech in 2008 and blending the resources of the two brands, the division is focused on both the OEM (as a provider of complete driveline systems packaged with AxleTech axles) and as an aftermarket performance gear supplier. US Gear’s primary OEM manufacturing is Eaton transmission shafts and differential parts for Dana.

US Gear has long established itself as a leader in the industry, and that’s a product of not only its technologies and the quality of its gears, but its focus on the manufacturing and the machinery necessary to develop a gear more efficiently and to a higher standard than many of its competitors.

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As US Gear’s Bob Angliss shares, a key part of this is their use of modern Phoenix cell CNC machines.

“With these machines, we can manufacture a part with one machine. Traditional methods used a five-cut ring and pinion machining process that used five machines — three machines were necessary to cut a pinion. You had a rough cut machine, and two finishing machines.  One for the coast side and one for the drive side of the gear. So you’d set that part up three different times on three different machines to get a finished part. Similarly, with the ring gear, there were two machines – one for the drive side of the tooth and another for the coast side of the tooth. But with the new CNC-controlled method, known as Duplex Completing, it’s one cut — you put the blank in and the gear comes out completed, the teeth are all there and it goes straight to heat treat.”

…with the new machines, they’re all CNC-controlled and it’s one cut — you put the blank in and the gear comes out completed, the teeth are all there and it goes straight to heat treat. – Bob Angliss

The net result of the Duplex method is not only greater efficiency, repeatability, and speed (some processes were reduced dramatically in machining time) in manufacturing, but a gear with a higher-quality cut on its teeth; in other words, an all-around better product.

From those machines, US Gear produces both their Competition and Street gear lines, which are cut from raw forgings. The parts arrive as rough forgings, which are placed into a lathe, to create blanks before going through CNC machining to create teeth.

US Gears’ Street gear is manufactured from an 8620 steel, which, per Angliss, is a standard grade of steel across the industry for ring and pinions. The Competition gear, meanwhile, is a line dedicated purely to racing and ultra-high performance applications, produced from a 9310 steel, which features a very high nickel content, making it extremely flexible for the harsh operating environment on the racetrack. The Competition gear, as Angliss shares, is purely for racing and “won’t survive on a road-going vehicle.”

US Gear supplies ring and pinions to such notable brands in the racing and performance market as Mark Williams Enterprises, Moser Engineering, and Strange Engineering. The company has also been the source of the gear sets in Chevrolet’s COPO Camaro drag racing package vehicles.

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One of the crown jewels in US Gear’s arsenal is their Lightning Series gears, which is a high-tech finishing process applied to their standard Competition and Street gears that provides a range of benefits to the customer. The Lightning Series is a gear that goes through a four-hour finishing process known as an Isotropic Superfinish (ISF) that was developed by a company known as REM Surface Engineering.

“With the Superfinishing, your part is sitting in a great big vibratory bowl of ceramic media of different shapes and sizes, paired with mild chemical accelerants to speed up the process. In a non-directional way — meaning you’re not rubbing everything back and forth in one direction — it’s taking all of the imperfections out of the surface and literally polishing them away; any machine marks, any imperfections in the steel. So anything left over from the manufacturing process, from turning to cutting tools marks, it’s removing,” Angliss explains.

In a non-directional way — meaning you’re not rubbing everything back and forth in one direction — it’s taking all of the imperfections out of the surface and literally polishing them away. – Bob Angliss

The benefits of this process are multi-fold: 1) there is no longer a need to perform a break-in on the gear. 2) It reduces friction, which reduces heat and improves component life. 3) It increases durability, because you’ve taken the tool marks out of the finish, thus creating less wear and in turn less maintenance. 4) It reduces the lubrication requirements and keeps the gear lube longer-lasting.

The Lightning Series, marketed as a gear line, is in fact purely a finishing process applied to either the Street or Competition gear range, with a part number and packaging differentiating it from the standard, non-Lightning finish should the customer opt to purchase it that way.

In all, US Gear’s aftermarket division includes over 250 different part numbers, comprising gear applications for Ford 8-, 8.8-, Super 8.8-, 9-, 9.5- and 10-inch; GM 8.4 and 8.6-inch and 12-bolt; early Chrysler 8.75, and Dana 60 rear ends; in every ratio one would ever need.

Us Gears' Competition (left) and Lightning Series ring and pinion.

With such a product lineup, and both the manufacturing and the engineering sides of the business on-point, US Gear is certainly poised for another half a century of success in the industry.