Dealing with a noisy rsx rear lower control arm is pretty much a rite of passage for anyone who's owned an Acura RSX for more than a few months. Whether you're driving a base model or a Type-S, that rear suspension setup is what gives the car its nimble feel, but it's also prone to some annoying wear and tear as the years pile on. If you've started hearing a persistent clunking or squeaking from the back end every time you hit a pothole, you're definitely not alone.
The rear lower control arm (often just called the LCA) is a pretty simple piece of hardware, but it does a ton of heavy lifting. It connects the bottom of the rear spindle to the subframe, basically acting as a pivot point that allows your wheel to move up and down while keeping everything aligned. When it's working right, the car feels tight and responsive. When it's not? Well, it can feel like you're driving a shopping cart with a bad wheel.
Why the Stock RSX Arms Eventually Fail
The reality is that most of these cars are now twenty years old, or at least getting close to it. The factory rsx rear lower control arm is made of stamped steel, which is durable enough for daily driving, but the real weak point isn't the metal itself—it's the bushings.
The OEM bushings are made of rubber, and over time, that rubber dries out, cracks, and eventually tears. Once the bushing is gone, you've got metal-on-metal contact or, at the very least, a lot of unwanted movement in the suspension. This "slop" doesn't just make noise; it actually ruins your alignment. If the control arm is shifting around, your toe and camber settings are constantly changing, which leads to your tires wearing out way faster than they should.
If you live in the "rust belt" or anywhere where salt is used on the roads in winter, you've got an even bigger problem: corrosion. The steel arms can rust, but the real nightmare is the bolt that runs through the bushing. It tends to seize to the inner metal sleeve of the bushing, making it nearly impossible to remove without a fight.
The Infamous Seized Bolt Problem
I can't talk about the rsx rear lower control arm without mentioning the "frozen bolt" issue. If you're planning to replace yours this weekend, listen up: start soaking those bolts in penetrating oil (like PB Blaster or Liquid Wrench) at least three days before you plan to pick up a wrench.
What happens is that the steel bolt and the metal sleeve inside the bushing become one through the "magic" of oxidation. When you try to turn the bolt, instead of it backing out of the subframe, it just twists the rubber bushing until the rubber snaps, or worse, you round off the bolt head.
If you find yourself in this situation, you've basically got three choices. You can try to use heat (a blowtorch), you can use an impact wrench and hope for the best, or you can go straight to the "nuclear option," which is using a Sawzall or a dremel to cut the bolt out entirely. Most RSX owners end up having to cut at least one of them. Just make sure you have replacement bolts on hand before you start cutting, because you aren't going to be reusing the old ones.
Stock Replacements vs. Aftermarket Billet Arms
Once you've finally gotten the old ones off, you have to decide what's going back on. You could just get some standard OEM-style replacements. They're cheap, they fit perfectly, and they'll probably last another ten years. But let's be honest, half the reason people look for an rsx rear lower control arm is to get those flashy aftermarket versions.
The Appeal of Billet Aluminum
Aftermarket LCAs are usually machined from billet aluminum. They look incredible, especially if you have a car that sits low enough for people to see the suspension from behind. Companies like K-Tuned, Skunk2, and Function7 have made these a staple of the RSX modding scene.
Besides the "bling" factor, there are some actual performance benefits. Aluminum is lighter than stamped steel, which reduces unsprung weight. This allows the suspension to react faster to bumps in the road. Most aftermarket arms also come with polyurethane bushings rather than rubber. Polyurethane is much stiffer, which means less deflection and more predictable handling, though it can make the ride feel a bit stiffer and sometimes introduces a little more road noise.
Spherical Bearings
If you're building a dedicated track car, you might even look at arms with spherical bearings. These get rid of the rubber/poly altogether in favor of a metal bearing. There's zero deflection here, giving you the most precise handling possible. The downside? They're noisy and they wear out faster in dusty, everyday driving conditions. For a daily driver, I'd stick with high-quality polyurethane.
How the LCA Affects Your Alignment
One thing people often overlook is how the rsx rear lower control arm interacts with the rest of the rear suspension. On the RSX, the rear camber isn't really adjustable from the factory. If you lower your car on springs or coilovers, the natural geometry of the suspension will cause the wheels to tilt inward at the top (negative camber).
While the lower control arm itself doesn't usually provide camber adjustment (that's usually handled by the upper control arm), the LCA provides the solid base for everything else. If you're upgrading your lower arms, it's the perfect time to check your rear camber kits and toe arms. If you're already under there with the car on jack stands, you might as well refresh the whole corner so you only have to pay for one alignment when you're finished.
Tips for a Smooth Installation
If you're going to tackle this job yourself, there are a few things that'll make your life a lot easier. First off, make sure you have a good jack and a sturdy set of jack stands. Never work under the car with just a floor jack holding it up—that's just asking for trouble.
- Disconnect the Sway Bar: You'll likely need to unbolt the sway bar end links from the control arms. These are also notorious for being seized, so hit them with that penetrating oil too.
- Support the Hub: When you pull the bolt out of the LCA, the whole spindle might want to drop or move. Using a second jack to slightly support the weight of the rear hub can help take the tension off the bolts, making them much easier to slide out.
- Don't Tighten Everything Yet: This is the most important tip. When you put the new rsx rear lower control arm in, just get the bolts finger-tight. You want to wait until the car is back on the ground with its full weight on the tires before you do the final torque. If you tighten the bolts while the suspension is hanging in the air, you'll "pre-load" the bushings, which will cause them to tear almost immediately once you drive away.
- Anti-Seize is Your Friend: When you're putting those new bolts in, slather them in anti-seize lubricant. Your future self (or the next owner of the car) will thank you immensely if the arms ever need to come off again.
Final Thoughts on Maintenance
At the end of the day, the rsx rear lower control arm is one of those parts that you don't think about until it starts making a racket. But once you swap out those old, tired steel arms for something fresh, you'll be surprised at how much "newer" the car feels. The rear end will feel more planted, the annoying squeaks will vanish, and you won't have to worry about your tires wearing out unevenly.
Whether you're just looking to get your daily driver back in tip-top shape with some OEM-style replacements or you're looking to add some color and performance with a set of billet aluminum arms, it's a solid investment. Just be prepared for those seized bolts, keep your cool, and remember that a little bit of grease goes a long way in keeping your RSX handling like it should.