GM 25840721 Front Drive Shaft Driveshaft Propeller 3.7L

( Brand: Gm ), ( Manufacturer Part Number: 25840721 ), ( Vintage Part: No ), ( Type: Driveshaft ), ( Transmission Type: Automatic ), ( Placement On Vehicle: Front )

Review GM Hummer 3.7l Front Drive Shaft Driveshaft Propeller Oem fits H3 4WD 2006–2010

The **GM 25840721 driveshaft for the 2006 2010 Hummer H3 3.7L 4WD Front Drive Shaft (Propeller Shaft)** is a precision-engineered, high-performance drivetrain component designed to deliver uncompromising durability and reliability in one of the most rugged and capable off-road vehicles of its era. This driveshaft is a critical link in the H3 s front-wheel-drive system, transmitting torque from the transfer case to the front axle while accommodating the vehicle s aggressive suspension travel, heavy-duty towing capacity, and demanding off-road applications. Crafted from high-grade, heat-treated steel, the driveshaft features a robust **U-joint (Universal Joint) assembly** at both ends, ensuring smooth power transfer even under extreme angles and loads, a necessity for the H3 s front-biased 4WD system. The **center bearing** is reinforced with a sealed, grease-packed housing to minimize wear and prevent contamination from dirt, dust, or moisture, which is essential for maintaining optimal performance in harsh environments. The driveshaft s **balanced construction** eliminates harmful vibrations, enhancing ride comfort while extending the lifespan of connected components like the transfer case and axle. Whether navigating rough terrain, hauling heavy loads, or simply driving through urban streets, this driveshaft is engineered to withstand the stresses of daily use without sacrificing performance. Its **direct OEM fitment** ensures compatibility with the 3.7L V6 engine s front-wheel-drive configuration, making it an ideal replacement for worn or damaged stock components. For owners seeking to restore their H3 s original functionality or upgrade for enhanced durability, this driveshaft is a dependable choice that upholds the vehicle s reputation for toughness and versatility.

### **Pros and Cons of Buying a 2006-2010 GM 25840721 Hummer H3 (3.7L 4WD Front Driveshaft/Propeller Shaft)**

#### **Pros**

1. **Strong Off-Road Capability** The Hummer H3 was designed for rugged terrain, with a high ground clearance, locking rear differential (on some models), and 4WD system. The 3.7L V6 provides adequate power for light off-roading and towing.

2. **Durable Build Quality** Early H3 models were constructed with a focus on robustness, featuring a reinforced frame, heavy-duty suspension, and a boxy, protective body style that resists dents and scrapes better than many SUVs.

3. **Spacious Interior** The H3 offers a large cargo area (up to 85.5 cubic feet) and comfortable seating for five, making it practical for families or utility use.

4. **Good Visibility** The tall, boxy design provides excellent forward and side visibility, which is beneficial for driving in rough or congested areas.

5. **Available Off-Road Packages** Some models came with optional features like skid plates, a snorkel, and a limited-slip differential, enhancing off-road performance.

6. **Modifiable & Customizable** The H3 has a strong aftermarket following, with options for lift kits, winches, off-road tires, and performance upgrades.

7. **Reliable 3.7L V6 Engine** The 3.7L V6 (used in the H3) is a proven, durable engine when maintained properly. It s not as powerful as later V8 models but is more fuel-efficient and less prone to major failures.

8. **Resale Value (for Enthusiasts)** While not a high-demand vehicle in general, Hummer H3s still hold some niche appeal among off-road and classic SUV enthusiasts.

---

#### **Cons**

1. **Poor Fuel Economy** The 3.7L V6 averages around **13-15 MPG combined**, making it expensive to operate, especially for daily driving.

- **Front driveshaft/propeller shaft wear** (as seen in your part number) This can lead to vibrations, clunks, or even failure, requiring frequent inspection and replacement.

- **Suspension components** (shocks, bushings, control arms) often wear out due to heavy use.

- **Electrical gremlins** Early models had issues with wiring harnesses, sensors, and infotainment systems.

3. **Rough Ride Comfort** The H3 s suspension is stiff and designed for off-roading, making highway driving uncomfortable for some drivers.

4. **Aggressive, Heavy Feel** The vehicle s weight (around **6,000 lbs**) makes it difficult to maneuver in tight spaces, and its boxy shape can be intimidating in urban settings.

5. **Outdated Safety Features** Early models lack modern safety tech like advanced airbag systems, stability control (though some had it), and poor crash test ratings compared to modern SUVs.

6. **Rust Concerns** Many H3s (especially in snowy or coastal regions) suffer from rust, particularly in the wheel wells, undercarriage, and frame.

7. **Limited Availability of Parts** While parts exist, some components (especially for older models) can be hard to find or expensive.

8. **Depreciation** The H3 has lost significant value over the years, and buying one used means you re likely paying a premium for its niche appeal rather than practicality.

9. **Front Driveshaft/Propeller Shaft Issues** The specific part you mentioned (GM 25840721) is critical for 4WD operation. If it s worn or failing, it can cause:

- **Unusual noises** (clunks, whines, or rattles)

- **Vibration in the cabin**

- **4WD disengagement or sudden loss of power**

- **Potential drivetrain damage if ignored**

This is a **major concern** if the driveshaft is failing, the repair cost can be **$500-$1,500 **, depending on labor and whether a new or rebuilt unit is needed.

10. **Environmental & Legal Issues** Some areas have restrictions on large, gas-guzzling vehicles, and the Hummer s size may limit parking or access to certain roads.

---

### **Ending Conclusion**

The **2006-2010 Hummer H3 (3.7L 4WD) is a capable off-road vehicle with a rugged, durable build**, but it comes with **significant drawbacks**, particularly in terms of **fuel efficiency, maintenance costs, and daily drivability**. The **front driveshaft/propeller shaft issue** you ve identified is a **critical red flag** if this part is failing, the repair will be expensive, and ignoring it could lead to **costly drivetrain damage**.

- **Off-road enthusiasts** who prioritize capability over comfort.

- **Owners who can afford high maintenance costs** and don t mind poor fuel economy.

- **Those who want a unique, heavy-duty SUV** for occasional use rather than daily driving.

- **Everyday commuters** who need fuel efficiency and low running costs.

- **Budget-conscious buyers** expect **$10,000 in repairs** over 5-10 years if not maintained properly.

- **Urban drivers** who value maneuverability and modern safety features.

---

### **Recommendation**

You **inspect the driveshaft thoroughly** (or have a mechanic verify its condition) and are **prepared for a potential $500-$1,500 repair**.

You **budget for high maintenance costs** (suspension, electrical, rust repairs).

You **use it primarily for off-roading or occasional heavy-duty tasks** rather than daily driving.

You **find a well-maintained example** (check service records for driveshaft, transmission, and suspension work).

You **accept the trade-offs** (poor fuel economy, uncomfortable ride, high insurance costs).

- **Used Toyota 4Runner (2010 )** More reliable, better fuel economy, still capable off-road.

- **Ford Expedition (2010 )** More comfortable, better safety ratings, still powerful.

- **Jeep Wrangler (JL or TJ)** More off-road focused, but with better long-term reliability.

- **Used Chevrolet Tahoe/Silverado (2010 )** More practical, lower maintenance costs.

The **H3 is a fun, capable off-road machine**, but **not a practical long-term purchase** unless you re prepared for its **high costs and limitations**. If you re set on buying it, **prioritize a vehicle with a verified driveshaft, full service history, and minimal rust**. Otherwise, consider a **more reliable alternative** that won t drain your wallet over time.

Details:

BODY TYPE: SPORT UTILITY 4-DOOR SUV. TRANSMISSION: 4-SPEED AUTOMATIC 4L60-E. MILEAGE: 165K MILES. DRIVE TYPE: FOUR WHEEL 4WD.

part #: 25840721 prices

• $69.00-$114.99

specifications universajoin:

• for models: H3, 4wd
• for makes: Hummer
• for years: 2006-2010
• brand: Gm
• mpn: 25840721
• vintage part: No
• type: Driveshaft
• transmission type: Automatic
• placement on vehicle: Front

offer universajoin:

• options: Ship-to-home
• sold: 0
• started: April 17, 2026
• best offers: True
• availability: In Stock
• quantity: 1

general universajoin:

• Transmission Drivetrain > Driveshafts Parts > Driveshafts
• condition: Used

returns universajoin:

• paid by: Seller
• time: 30 Days
• policy: Returns Accepted

seller universajoin:

• rating: 99.9%
• # reviews: 57095
• city: Kingsley, Michigan

payments universajoin:

• other
• wallet: Apple-pay
• credit card: Discover

shipping universajoin:

• service: Economy
• transit: 4-8 Days
• cost: $50.00
• class: Economy
• type: Fixed

Gm 25840721 Is Similar To:

• Rear Corvette used Drive 10054289-8ym Gm C4 Shaft Trans 84-96 Automatic (29.5% similar) ...(June 1st, 2015)
• 10054299 Corvette Manual Transmission Aluminum Driveshaft Gm (30.8% similar) The drive shaft is balanced and in good condition with some light pitting on finish. Shipping only to the lower 48 Continental USA. Used aluminum drive shaft from a 1995 corvette c4 with manual 6-SPEED transmission...(November 7th, 2018)
• 10223032 Gm Corvette Rear Half Shaft Aluminum Auto Or Stick Used (25.9% similar) Why go to dealer and pay a arm leg for the same thing, when you can buy here. I AM's corvette guy since the old age of 17 years and 58 young. Mistakes happen, it is only human. I have been selling this weatherstripping for 20 years incredibly with super satisfied buyers that's why make the claim no ...(January 19th, 2019)
• 10783 Gm Nos Chevrolet Car Truck Drive Shaft Bushing And Seal (36.1% similar) Nos, or new old stock does not mean the part is mint even perfect. This is a discontinued Gm part. Measures ol x od id states only. Gm why settle for reproductions when you can have the original factory item that is meant and will fit your vehicle. Original boxes can be missing a flap or torn. ...(June 27th, 2018)
• 11102301 Gm Chevrolet Oem Cruze Drive Shaft Ring (32.1% similar) Est, Mon to Fri. All airbag modules are also non returnable...(August 11th, 2018)
• 11570807 Gm New Pack Genuine Oem Joint Coupling Bolts (19.1% similar) Genuine oem Gm drive shaft rear u-joint grunion to yoke bolts. Please verify for yourself that this part will work your specific year make model vehicle before purchasing. Fits 08-'15 Buick enclave, 09-'15 Chevy traverse, '07-'15 GMC Acadia, maybe others. In sealed factory package...(May 28th, 2018)
• 12369463 Gm Brand New Genuine Oem Drive Shaft Snap Ring (33.3% similar) All of Tosca's top quality oem replacement parts are backed by a 12 month 12,000 mile warranty...(September 26th, 2018)
• 12385742 Joint Oem-universal Gm (22.8% similar) ...(March 20th, 2015)
• 12456224 Gm Torque Tube Propeller Shaft Driveline Oem Vette Cyl Auto (35.8% similar) Parts that have any electrical pieces or components are not returnable. Please evaluate the carrier FedEx or USA post office, service type, cost and estimated delivery date. If you are outside the 48 contiguous states or need faster delivery service, please before purchasing item...(October 24th, 2018)
• 12471617 Acdelco Gm Original Equipment Drive Shaft Seal (34.8% similar) 3i sport utility 4-DOOR, aery base XXL plus Denali limited linear ls LTZ north faces SLE SLT ss 4-DOOR...(May 10th, 2018)
• 12472424 Bearing Gm Oem Rear-center (22% similar) ...(April 13th, 2015)