Guide to 2003-2008 Isuzu Ascender Wheel Bearing Hub Assemblies
Hearing a roaring or humming noise from your wheels? It's a common sign of a failing wheel bearing on your Ascender.
- The Ascender uses a complete, bolt-on wheel hub assembly that includes the ABS sensor.
- Symptoms include a loud humming/roaring noise that changes when turning, steering wheel vibration, and an ABS light.
- Premium aftermarket brands like SKF and FAG offer OEM-level quality and longevity, while economy brands are cheaper but may not last as long.
- This part is shared with many other GM SUVs like the Trailblazer and Envoy, making it widely available.
Is Your Ascender's Wheel Bearing Failing?
A bad wheel bearing is a common issue on the GMT360 platform, which your Isuzu Ascender shares with the Chevy Trailblazer and GMC Envoy. The most common symptom is a loud noise coming from one of the wheels. This noise is often described as a humming, roaring, or grinding sound that gets louder as you drive faster. A good way to diagnose which side is failing is to notice if the noise changes when you turn. For example, if you turn left and the noise gets louder, the weight of the vehicle is shifting to the right side, putting more stress on the failing right-side bearing.
🎬 Listen to the specific sounds and symptoms of a bad bearing.Other Symptoms of a Bad Wheel Bearing:
- Vibration: You might feel a vibration in the steering wheel, which can worsen at higher speeds or while turning.
- ABS Light: Since the ABS sensor is part of the hub assembly, a failing bearing can damage the sensor or its wiring, causing the ABS warning light to come on.
- Loose Steering: The steering may feel less responsive or 'sloppy' due to excessive play in the worn bearing.
- Pulling to One Side: A failing bearing can cause the vehicle to pull to one side.
Choosing the Right Aftermarket Hub Assembly
Since your Ascender is a rebadged GM product, the original (OEM) parts were likely made by a major bearing manufacturer. High-quality aftermarket parts can be just as good, if not better, but there is a wide range in quality. The price often reflects the expected lifespan of the part.
Brand Quality Tiers
When shopping for a replacement, you'll find brands in a few different categories:
- Premium Brands (SKF, FAG, National): These are top-tier manufacturers known for producing original equipment for many carmakers. Brands like SKF and FAG are respected for their high-quality steel, precision engineering, and durability. They are often the most expensive aftermarket option but provide the longest service life, comparable to the original part.
- Mid-Grade Brands (Beck Arnley, GMB): These brands often provide a good balance of quality and cost. Beck Arnley is known for sourcing parts from various quality manufacturers, while GMB is a known OE supplier for some carmakers. Quality can be very good, but it's important to check reviews for the specific part number.
- Economy Brands (WJB, IAP Hub Assembly, MPA): These are the most affordable options. While the low price is attractive, forum discussions and mechanic reviews often suggest these bearings have a much shorter lifespan than premium or mid-grade options. They may be a suitable choice for a vehicle that isn't driven daily or if budget is the primary concern, but be aware that you might be replacing them again sooner.
Pro Tip: The Isuzu Ascender shares its wheel hub assembly with the 2002-2009 Chevrolet Trailblazer, GMC Envoy, 2004-2007 Buick Rainier, and 2005-2009 Saab 9-7X. This can make it easier to find parts from a wider variety of suppliers.
| Part Type | Estimated Cost (Part Only) |
|---|---|
| New Aftermarket (Economy) | $22.71 - $45.00 |
| New Aftermarket (Mid-Grade/Premium) | $45.00 - $83.44+ |
| Shop Labor | $159 - $233 per wheel |
Frequently Asked Questions (FAQ)
Should I replace wheel bearings in pairs?
It is highly recommended. If one wheel bearing has failed due to mileage, the other one on the same axle has experienced the same amount of wear and is likely not far behind. Replacing them in pairs ensures consistent performance and saves you from having to do the same job twice in the near future.
What is the difference between a wheel bearing and a hub assembly?
A wheel bearing is the set of steel balls or rollers that allows the wheel to spin. A hub assembly is a complete unit that includes the bearing, the hub flange, and the ABS sensor. The 2003-2008 Isuzu Ascender uses a sealed hub assembly, which is a bolt-on part that makes replacement easier than pressing individual bearings in and out.
Is this a difficult job to do myself (DIY)?
For a mechanically inclined person with the right tools, this is a very feasible DIY job. It involves removing the wheel, brake caliper, and rotor, then unbolting the hub assembly from the steering knuckle. It does not require a hydraulic press. 🎬 Watch this step-by-step guide to replacing your Ascender's hub assembly. However, the axle nut can be very tight and the hub can be rusted into the knuckle, so a good breaker bar and penetrating oil are essential.
Do I need a different part for 2WD vs. 4WD?
For the front axle on this platform, the hub assembly is the same for both 2WD and 4WD models. The hub has a splined center to accept the CV axle on 4WD models, and on 2WD models, the axle shaft is simply not present. Always confirm fitment with the seller before purchasing.
Were there any recalls for the Ascender wheel bearings?
No, there were no specific recalls issued by the NHTSA for wheel bearings on the 2003-2008 Isuzu Ascender. While there was a recall for wheel bearing bolts on some Isuzu commercial trucks, this did not apply to the Ascender. The failures are considered a common wear-and-tear issue for this vehicle platform.
Helpful Videos
Technical Specifications
OEM Part Numbers: 8-97365-946-0 513188
The front wheel hub assembly for the 2003-2008 Isuzu Ascender is a 6-lug, 3-bolt flange design that includes an integrated ABS sensor. It is interchangeable between the driver and passenger side and fits both 2WD and 4WD models.
We Have This Part in Stock
The information in this article is provided for general reference and educational purposes only. Vehicle specifications, procedures, and part compatibility can vary by production date, trim level, and region. Always consult your vehicle's factory service manual and verify part numbers before purchasing or performing repairs. Safety-critical components such as airbags, seat belts, and braking systems should be installed by a qualified professional.
- Isuzu Ascender: