Putting the R&D in TRD

Putting the R&D into TRD

Let’s talk TRD!

Did you know that Eibach has been the OEM spring supplier for Toyota and Lexus performance vehicles since 1998? After years of success with the manufacturer, Eibach has now been the OEM supplier for Toyota Tacoma, Tundra and 4Runner Off-Road vehicles since 2016, too. Do you have any idea how much work is involved in providing parts for factory-fresh, OEM vehicles? A lot! But that’s what we do here – we’re up to the task.

Enter TRD Pro; the tip-top of the line in off-road prowess from Toyota Racing Development. Now, while we provide the springs for these new trucks off the showroom floor, they’re made within OEM specifications and heights. While immensely capable out of the box, the TRD’s are notorious for too much front rake and brake diving, with looks leaving a lot to be desired. So, we went to the drawing boards to correct this height problem while adding ground clearance and capability, with looks to match.

Sounds easy, right? Well, let us walk you through exactly how we make our way from idea to execution with our TRD Pro kits.

First things first, we’ll bring in a stock vehicle to evaluate. Fortunately, we’ve got a full-service shop here at our Corona facility, with lifts, tools and good techs to boot. Measurements for stock ride heights and reference points are recorded, and then we’ll disassemble the factory suspension to gather statistics and rate the springs.

Unique to the TRD PRO’s are FOX shocks coming standard from the factory. These are no joke, and they’re packed with high level tech and features.

Welcome to the Bypass Zone. The FOX shocks have an internal bypass system used to move fluid around in different routes to guarantee a smooth ride on the road, while also being able to perform off-road. Without putting you to sleep on the ins and outs of fluid dynamics, bypass technology is there to make your life better, and it’s precisely tuned to control wheel travel at each corner of the car, making the characteristics of each shock different than one another in varying situations – basically, it’s like having four different shocks! So, why are we talking about this? Well, a major part of our spring package’s success rides on finding the bypass zones. Fortunately, we have the technology to do just that!

With our state-of-the-art Gardner Shock Dynos, we’re able to cycle the shocks in 5mm increments to find the bypass zones. Once identified, we can determine the lift for our springs. A major goal for the TRD kit is to level the front of truck out with the rear, optimizing height and travel in the operating range of shock.

Finally, once the data is collected, it is prototype time. We set our engineers loose and design multiple prototype sets to test on the stock TRD Pro vehicle once it’s brought back into the shop. We’ll check fitment and go through all the same steps that we did when the vehicle was initially brought in. We take our time at this stage, but usually at this point, the team is getting excited for the best part of R&D: real-world testing.

In this case, we hit the trails and seek rugged environments for our engineers to put these springs through their paces. What we’re looking for are any discrepancies, noises and of course, poor ride quality. With hours and miles on the clock, we’ll make sure the whole team from engineering to marketing to sales has a chance to test the prototype further, and once it’s approved, the final product is ready to go into mass production!

Each spring, although aftermarket, is put through the same process as the OE TRD Pro springs are before they’re ready to be put on the shelf.


Each spring begins life as a 4,000-pound coil of ultimate strength steel. The springs are tempered to balance certain stress peaks and increase endurance. The surfaces are ground perfectly square to minimize side loads, and through shot peening, max stress levels are dramatically increased. We’ll then pre-set the springs, meaning, we’ll compress the springs to block-height to avoid sagging in the future, a symptom commonly found with lower-grade springs. Pre-setting also ensures the preservation of load and deflection characteristics, which are integral to continued performance.

We pride ourselves on putting out quality products – the kind of parts we want on our own cars, and the quality Toyota trusts. It’s for this reason, our quality assurance system is the strictest in the industry. We rigorously check and guarantee all critical data for each part at the end of its manufacturing process, with extremely narrow ranges.

Finally, what was once that 4000-pound coil, is now ready to be a finished spring as it enters its corrosion protection phase. Our spring protection is a mixture of phosphating and powder coating to protect against abrasion and corrosion, and of course, look cool, as these springs are color matched to the OEM TRD Pro red.

And that does it! A part you can order online with the click of a button, install quickly with no issues and have instant, awesome results with, has had a longer coming-to-life story than you might have thought. Want to hear more about engineering and how it’s made? Ask us some questions! We love nerding out about this stuff.

Stay tuned, as we have more TRD Pro projects in the works. That’s right, Tacoma ’17-’19, Tacoma ‘20+ and Tundra.

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