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Sonnax designs, develops and manufactures the highest quality aftermarket automotive products. We are the world’s largest full-line supplier of torque converter parts, and offer transmission and specialty driveline components through a global network of parts distributors.

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Latest News

October 13, 2023

Rostra Adds 13 OEM/S Solenoids & Modules

Sonnax Transmission Company is excited to announce the addition of 13 solenoids and modules to the Rostra Powertrain Controls product group beginning this October. The company has secured these SKUs in an agreement to succeed BorgWarner as the distributor for their OE solenoid supplier, Solero Technologies.

This distribution program represents an important opportunity to support the Sonnax mission: to be the leader in bringing innovative, high-quality drivetrain components to the automotive aftermarket. 

Look for this icon at to identify authentic OEM/S parts supplied by Rostra and contact your distributor today!


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March 31, 2023

Top Shop Product Winners of 2023

Every year, Transmission Digest accepts nominations for the top products and tools in the powertrain aftermarket. Readers vote for their favorites to determine the winners. The results are in: we won 13 top product awards! Thank you all for your trust and support of Sonnax and Rostra products – we couldn’t have done it without you.

Take a look at the winning products here:


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March 16, 2023

JTEKT North America – Koyo® Bearings Notice

The automotive aftermarket has long been familiar with Torrington bearings. Although most people know that Torrington is a company that manufactures these bearings, the term “Torrington bearing” has become synonymous with needle roller thrust bearings. “Torrington bearing” has become a generic term describing a type of bearing as much as it indicates a manufacturer who produces those bearings.

The Torrington Company was established in 1898 in Torrington, Conn. It was an independent company until an acquisition by Ingersoll Rand Corp. in 1968. In 2003, Torrington Bearing was sold to the Timken Company, which produced Torrington brand bearings until 2009. In 2009, JTEKT Corporation of Japan acquired the Torrington bearing line – including the manufacturing plants and tech center along with 3,400 employees – from Timken. Torrington became part of the JTEKT’s Koyo Bearings.

Since 2013, these products formerly known as Torrington bearings were marketed solely under the Koyo brand name.

In April and November 2022, JTEKT North America provided notification regarding the unification of the Koyo bearing brand to the JTEKT brand. Be aware there is no change in ownership associated with the name change. This change is simply a consolidation of the Koyo bearing brand to the globally recognized JTEKT brand.

JTEKT Bearings — changing its name from Koyo Bearings — is the Torrington Legacy, and you can count on Sonnax providing you with the same great OE quality you've always received under the Torrington brand... only the name has now changed to JTEKT.

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Join an exciting front-line team focused on developing and delivering the best products in the industry, a team whose imagination, hard work and results are rewarded.

After decades of serving the transmission aftermarket as standalone companies, Sonnax and Rostra Powertrain Controls integrated in 2021 to become a single, transmission-focused organization.

Our 200+ employees proudly serve the automotive aftermarket with the Sonnax and Rostra Powertrain Controls brands, and strive to further the company’s reputation for excellent service, technical knowledge and customer dedication.

Sonnax Transmission Company headquarters is in Bellows Falls, Vermont, with production facilities in Laurinburg, N.C. and technical development centers in California, Georgia, Indiana, Missouri and Wisconsin. Rostra Powertrain Controls’ production facility is in Laurinburg, N.C.

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