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The Symptoms

You’re driving along in your Lexus IS350 and you start to notice a “womp, womp, womp” noise coming from your front wheel. If this has happened to you, you’re not alone. This is a common issue on the 2nd generation Lexus IS350 and is known to be caused by a failing wheel hub assembly. This was the symptom that I experienced that led me to believe the front wheel hub needed to be replaced.

2nd gen lexus is350 rear wheel

Keep in mind that there are a variety of irregularities that you may experience that can be symptomatic of a bad wheel bearing. Another thing you may hear is a constant howling while driving.

Essentially, checking for a bad wheel bearing involves looking for play in the wheel while moving it side-to-side and up-and-down. If there is play in the wheel in both directions while at the same time having no movement in the upper or lower control arms or tie rod, then it is indicative of a bad wheel bearing. However, understand that just because there is no play in the wheel hub, doesn’t mean it doesn’t need to be replaced.

Validating the Problem

When I experienced this noise coming from the front left wheel, I thought the wheel itself was the cause. After rotating the tires, I noticed that the noise was still coming front the same place, the left front wheel.

Also while driving, I’d pay close attention to the frequency of the noise as I tried different things. When I was making a left through a curve, I’d notice that the sound went away. As I was making a right through a turn, the noise would be more pronounced. This substantiated the fact that the issue was on the left side.

While making a left through a curve, the weight of the vehicle shifts to the right side, resulting in less weight on the tires on the left side of the vehicle. Doing the same thing with a right through a curved turn, and the opposite happens. When more weight was on the left side of the vehicle during right turns, the the noise was more audible. This confirmed that the issue was on the front left wheel hub rather than the right.

Pricey Lexus IS350 Wheel Hub Parts

Although the issue was with the front left wheel hub bearing, I decided to get both sides replaced as it is possible the right side is on its way out as well. When I got the quote from a mechanic on the cost to replace the wheel hub, I was quoted 2 hours of labor to do each side (front left and front right), as well as a cost of $400 in material cost for each wheel hub assembly. That’s $800 for two wheel hub assemblies!

Usually mechanics stick with OEM parts; that is totally understandable. It’s reliable, guaranteed to fit, and they normally can get these parts delivered to them quickly so they can get your car back to you quickly. Unfortunately, they tend to be much more expensive. Obviously, they’re not taking their time shopping for a deal. Since I wasn’t in any hurry to get this work done, I started looking into aftermarket options and alternative OEM options.

OEM Parts

First, I looked up the part numbers of the parts that I needed on several OEM Lexus Parts Search websites and cross-referenced them with other websites to make sure I had the right part numbers. Sometimes, part numbers are replaced by the car manufacturer with an updated part number. In this case, here’s what I discovered:

Front Left: #43560-30010 (original part number) replaced by #43560-30011

Front Right: #43560-30020 (original part number) replaced by #43550-30021

OEM front wheel hub assemblies go for about 75% the cost quoted by the mechanic. Not bad, but I still want to explore other options…

Aftermarket Parts

It’s really hard to trust the no-name aftermarket brands that you find on eBay, so I like to take a gander at the parts available on RockAuto.com. They offer a wide selection of both aftermarket and OEM parts usually at very reasonable prices. I think it’s great that they categorize the available parts by Economy, Standard, Performance, Premium, etc. so you can decide what’s best for you. Furthermore, RockAuto tends to place the equivalent OEM part numbers on the corresponding parts they sell so it’s easy for you to determine if you’re getting the right part or not.

Branded OEM

is350 wheel bearing aftermarket

It’s not uncommon to find part companies build parts for car manufacturers. It’s very possible to find the exact same part at any Toyota Parts Department and also through the part company’s catalog.

In this particular case, it appears that Koyo is a Japanese part manufacturer who built and provided the wheel hub assemblies to Lexus for the IS350. I ended up finding Koyo branded wheel hub assemblies on eBay with the corresponding OEM part numbers.

The price ended up being about $120 for each wheel hub assembly compared $400 OEM part through the mechanic and $320 OEM part through eBay.

Front Left: #43560-30010 (original part number) replaced by #43560-30011
OEM Part / Koyo-Branded Part

Front Right: #43560-30020 (original part number) replaced by #43550-30021
OEM Part / Koyo-Branded Part

I provided the purchased Koyo parts to the mechanic, had them replace the two front wheel hub assemblies, and perform a wheel alignment. I got the car back and drove it home, and all of the growling noises I heard previously were completely gone. I saved myself about $550 in parts and now have an IS350 that is back to running quietly and smoothly.

A word of warning: the Koyo parts come with their own set of proprietary part numbers that don’t necessarily match the OEM ones. Therefore, when you receive your parts in the mail, mate the part up with the respective order that you placed. The eBay listing and order should state whether that particular part is for the front left or front right. Use that information to determine the part that you receive and make note of it to ensure proper fit on each side of the car.




Hi there! I'm Scott and I run The Track Ahead. My goal is to provide helpful articles and tutorials based on my experience and research related to car maintenance and automotive detailing. When I'm not writing and not working my day job, you can find me spending time with my family and working on home and car projects.

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