Truetrac for Mustang – 2015+ S550 Available NOW

Truetrac Posi Limited Slip 2015 2016 2017 2018 2019 2020 2021

The NEW Truetrac for Mustang is HERE!

The Truetrac for Mustang is a great choice for anyone who wants smooth and maintenance free traction. The beauty of the Truetrac is that you’ll never know it’s there until you need it. Burn out like a boss! Get your Truetrac today.

Check out our Catalog Page for the Ford 8.8″ Differential

Video of how the Truetrac works.

About Our Company


Our specialty is Differential, Gear and Axle parts – That’s all we do!  This focus has allowed our parts and tech team to become experts in their field. At West Coast Differentials, we take pride in what we do. We are a family owned and operated business with a single location in Northern California. We service the nation from that location.

We are technical advisors and problem solvers, not just order takers. As of 2023, our parts specialists have more 90 years of combined experience.

What we Don’t Do

We only sell differential and axle internal parts for rear-wheel and four-wheel drive vehicles. We don’t sell parts for front wheel drive vehicles or transaxles. We don’t sell housings or brake parts. We don’t sell steering parts like rack and pinions or tie rod ends.

Our Goal

Our goal is to provide the highest quality parts and customer service in the business. We don’t sell parts online because we want to make sure you get the correct parts in the shortest possible time. Sales are conducted over the phone and our advice and expertise is free of charge. We will provide you with the best possible solution to fit your performance needs and budget. Our everyday prices are always fair, and we don’t try to lure customers in with loss leader promotions.


Orders placed before 4PM Pacific Standard time are almost always shipped out the SAME DAY that you order, with the exception of special order or non-stock parts.

Returns, credits and exchanges are handled quickly, because we know it’s frustrating to wait for these transactions. We don’t want to keep your money tied up any longer than is absolutely necessary.

If you’re looking for a reliable source for gear and axle parts, give us a try! We think you’ll be glad you did.

 At West Coast Differentials, We Make the Difference!