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.Where to Buy
Enter a Sonnax part number below to view its instructions. For general reaming instructions, click here.
TWO THUMBS UP. I am a loyal user of Sonnax products and they are a company that puts their customers first. Thank you for great products, and I look forward to future products!B. Cole, Toronto, ON
Uniquely designed to fit all '99-later Chrysler 45/545/65/66/68RFE applications – regardless of OE checkball or solenoid configuration.
Easily repair and prevent chronic bushing failure while saving the OE shaft with this unique, patent-pending kit.
Prevent transmission failure due to cracks and wear with high-strength 4140 billet steel direct replacement.
My customers depend on me to keep their vehicles on the road. I depend on Sonnax to help me do that. Thanks Sonnax!S. Moore, Moore's Transmission
Heads up! We’re taking a few days off for the holidays to spend treasured time with our families and enjoy the festivities.
Sonnax will be closed:
Thank you for all your support. Wishing you a happy, healthy and prosperous New Year!
Enter to win one of three $100 Visa gift cards plus a cool Sonnax swag bag!
You have until 11:59 p.m. on Dec. 31 to submit your entry. Three lucky winners will be chosen at random and announced on Friday, Jan. 7.
Good luck and Happy Holidays from all your friends at Sonnax!
Official Rules: No purchase necessary. Open to U.S. residents aged 18 and older. One entry per person. Except where prohibited, participation in the Sonnax giveaway constitutes winner's consent to Sonnax use of winner's name and comment for promotional purposes in any media, worldwide.
Sonnax Transmission Company is excited to announce a recent reorganization, integrating Rostra Powertrain Controls into the company’s Vermont- and North Carolina-based Sonnax operations. This concludes several years of internal moves aligning teams and resources to better serve the transmission aftermarket. Both the Sonnax and Rostra brands have been part of Marmon Holdings, Inc. since 2018, with Steve Boyer leading both teams as President since 2020.
“Through this integration, Rostra and Sonnax will become a single, transmission-focused organization,” said Boyer. “This new structure will synchronize our product development efforts, reduce time to market of new products and allow us to make improvements in quality and delivery to our shared customers.”
Boyer said several internal promotions were made to support the alignment of both brands under Sonnax Transmission Company:
Maura Stafford is appointed company Vice President of Transmission Products. Stafford and her team manage product groups focused on hydraulic and electronic transmission components, solenoids and remanufactured valve bodies.
Steve Jaussaud continues as company Vice President of Product Line Management, guiding development of torque converter, high performance, driveline and mechanical transmission components. Jaussaud also manages the torque converter product line, a responsibility he assumed in late 2020.
Beth Houder is appointed company Vice President of Marketing & Communications, leading marketing efforts and the continued development of both brands in the aftermarket industry.
Mark Kaplan serves as company Vice President of Sales, assuming sales management for Sonnax and Rostra. He is joined by Seth Baldasaro, Director of Strategic Accounts, and Tony Diorio, National Accounts Manager.
I am a Sonnax fan because no matter if I am rebuilding an everyday transmission or a race transmission, I can trust the quality of the Sonnax parts I choose.C. Lentech, Lentech Automatics
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Sonnax tools save me time, money and come backs, I use them on every rebuild we do in my shop.E. Sebris
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.Careers at Sonnax
All of Sonnax product lines are top notch. I use Sonnax on all my builds.
F. Lane, FastLane Racing Transmissions