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National Transmission, Inc.
About Us
Based in Portage, IN, National Transmission, Inc. is your trusted destination for exceptional transmission services and a comprehensive range of automotive solutions. Serving Portage and the surrounding communities, our skilled team specializes in transmission repairs and excels in various auto services, including brake repair, radiator repair, engine repair, coolant system maintenance, towing, small engine repair, vehicle diagnostics, routine car maintenance, and 4x4 service. Rely on National Transmission, Inc. for outstanding service and dependable solutions for all your vehicle needs.
Areas Served
Portage, IN | Valparaiso, IN | Hobart, IN | Merrillville, IN | Chesterton, IN | Crown Point, IN
What We Offer
Our Services include:
- Transmission Service
- Auto Repair
- Brakes
- Brake Repair
- Radiator Repair
- Engine Repair
- Coolant System Repair
- Towing Services
- Small Engine Repair
- Vehicle Diagnostics
- Car Maintenance
- 4x4 Service
- Shocks & Struts
- Tune Ups
- Oil Changes
- AC Repair
Our Products include:
- Batteries
- Transmissions
Testimonials
On 4/5/2026
Shellie Barron
had this to say:
They were highly recommended to me by the owner, Sonny of USA Muffler in Valparaiso. These people showed respect, honesty & value! They rebuilt my complete transmission in a short period of time. The shop crew & well as the front desk treated me & my vehicle extremely well!! A Fantastic team They have there! They do more than just transmissions.
On 4/3/2026
Jimmie Piper
had this to say:
Excellent people and service je went above and beyond what was expected and worked with me I recommend these guys respectful and honest thank you guys
On 9/28/2025
Kathleen Hochberg
had this to say:
Professional friendly and cost efficient
Testimonial written by Kathleen Hochberg on this site.
On 9/16/2025
Mick Gut
had this to say:
My family and Ivalways come here..great bunch of guys and always great service at a great cost.
On 7/7/2025
Karen Feczko
had this to say:
Great customer service. Repaired in a timely manner.
Contact Us
National Transmission, Inc.
5475 US Hwy 6 Portage, IN 46368
Phone: (219) 762-2228
Fax: (219) 763-2029
Email: tranzman23
Where To Find Us
Follow us on FacebookOur Hours
Holiday Hours May Vary. Please Call For Details.
Monday: 8:00 AM - 5:00 PM
Tuesday: 8:00 AM - 5:00 PM
Wednesday: 8:00 AM - 5:00 PM
Thursday: 8:00 AM - 5:00 PM
Friday: 8:00 AM - 5:00 PM
Saturday: 8:00 AM - 12:00 PM
News
When your car needs reliable care, National Transmission Inc. is your trusted local team in Portage, IN. From expert transmission repair and rebuilds to full auto repair, brake service, diagnostics, and routine maintenance, their experienced technicians handle both foreign and domestic vehicles with precision.Locally owned and operated, National Transmission provides prompt service backed by a 100% parts and labor nationwide warranty, giving you peace of mind every mile you drive. Whether you need engine diagnostics, an oil change, or transmission service, they’re committed to keeping your vehicle running safely and efficiently.
👉 Visit NationalTransmissionPortage.com to schedule your appointment today!
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