Tesla would not be the EV juggernaut we know today without its obsession with innovation. Time and again, Tesla defies convention in pursuit of EV performance, and the resulting cars and SUVs certainly stand apart from the crowd. Here at Dorman, we think innovation is great, but maybe not on every piece of a car, as Tesla owners discovered when control arm and ball joint assemblies began failing on some Model 3, Model X, and Model Y vehicles.

Tesla’s approach to control arms was an innovative one: ball joints are carried in control arms making use of hybrid construction, combining steel and a rugged polymer composite called fiber-reinforced plastic (FRP). Both materials are strong, lightweight, and cost-effective, but the longevity and ultimate strength of this design has been called into question. Tesla Model 3, X, and Y owners noticed creaking, premature wear, and failure from these ball joints. There are even documented incidents of these ball joints completely separating from their sockets.

Your customer won’t need to worry about creaks, clunks or insidious rust.

As suspension experts, we immediately recognized these common symptoms of unchecked corrosion in a ball joint assembly. We also noticed that replacement arms from Tesla still did not include a solution for sealing moisture out of the socket. When we analyzed Tesla’s design in failed units, we found moisture damage. Here’s why: the original arms feature a plastic cap that covers the ball joint, but the lip of that cap sits at the lowest point of the arm when the vehicle is stationary. Water creeps under the cap and is trapped, and the ball joint is the victim.

Suspension Control Arm And Ball Joint Assembly

527-513

527-513/514 (Top): Tesla 3 2023-17, Tesla Y 2023-20

527-511

527-511/512 (Bottom): Tesla X 2023-16

Tesla issued a recall (20-31-006) for affected control arms, but their official repair was just a bead of caulk to seal up the cap’s open end. This fix was especially ineffective for vehicles that had already developed rust. A ball joint that’s creaking from corrosion will already have pitting around the ball and socket. While preventing further water ingress can’t hurt, it can’t help, either. The damage is done.

Dorman’s new line of OE FIX Tesla control arm and ball joint assemblies features substantial design changes to actually address the flaws caused by the factory design, rather than the questionable attempt recommended by the factory TSB to make it through a warranty period. After all, the creaking isn’t going to stop, is it?

Tesla Problem Tesla Fix

Tesla OE shield traps water, while Dorman OE FIX™ keeps water out.

When addressing the arm that fits the 3 and Y (527-513 and 527-514), the first thing we tackled was the arm’s makeup. We eliminated the FRP and reverted to that old standby: steel. Right off the bat, this increases arm stiffness by 30 to 50 percent. To keep that steel in service for a long time, we selected an electrostatically-applied coating to prevent corrosion. Next, we turned our attention to the ball joints themselves. We eliminated the cap Tesla used, allowing water to evaporate naturally instead of lingering and damaging the ball joint’s internals. We include the necessary hardware to install each arm to make the swap as painless as possible.

These arms are a good example of an OE FIX that replaces an unconventional (and unreliable) OE part with a tried-and-true design. Sometimes blinding innovation isn’t always the best choice.

FRP Problem FRP OE FIX

 Tesla OE FRP compared to Dorman OE FIX™ steel

When we turned to the arm for the X, we applied the same fixes but took things even further. Dorman’s OE FIX control arms for that model (527-511 and 527-512) use fully sealed ball joint housings that have been precision engineered and manufactured to our specifications. There’s no cap because there’s no seam! Instead, that housing is made from a beefy, one-piece forged billet of steel that’s then riveted to the steel arm, a tough and traditional answer to a modern problem.

We’re fairly certain that this decidedly traditional approach to building arms will still be received warmly by the owners of these groundbreaking vehicles. We’ve been serving the aftermarket with quality control arms for decades, and we’re proud to bring our expertise to the most popular EVs on the road today.

Whether you’re replacing a failed arm on a Tesla, or preemptively installing a full set of our arms to avoid problems down the road, your customer won’t need to worry about creaks, clunks, or insidious rust hiding under the surface. Save your caulk for the kitchen sink.