Description
Product Overview
The BLKPRO spindle hub seal is a precision‑engineered component designed for diesel truck applications. Constructed from high‑grade rubber compounds, it provides excellent resistance to oil, heat, and wear. Weighing just 1 lb, the seal is easy to handle while maintaining robust durability. It matches the manufacturer part number 3969999 and fits a broad spectrum of engine families including ISB, QSB, QSC, 4B, K38, and many agricultural and industrial models.
Usage
This seal is ideal for replacing worn or damaged spindle hub seals in diesel trucks, generators, and heavy‑duty equipment. Install it during routine maintenance or after a hub failure to restore proper lubrication and prevent contamination. Suitable for professional mechanics, fleet service centers, and experienced DIY enthusiasts working on trucks, gensets, and agricultural machinery.

Why Choose Us
BLKPRO is renowned for manufacturing reliable automotive components. Our spindle hub seal undergoes strict quality control, ensuring consistent dimensions and material integrity. Backed by a reputable brand and a proven track record in the automotive replacement market, this seal offers peace of mind and long‑term performance.
Key Features
- Durable high‑temperature rubber for extended service life
- Lightweight 1 lb design for easy handling and installation
- Broad compatibility with ISB, QSB, QSC, 4B, K38 and related models
- Precision fit to manufacturer part number 3969999
- Designed for diesel engine and heavy‑duty applications
FAQ
What vehicles are compatible with this seal?
The seal fits a wide range of diesel trucks and equipment, including models designated ISB, QSB, QSC, 4B, K38, B5.9, 6B, QSM11, ISM11, ISX15, QSX15, N855, N14, M11, B6.7, K19, NT855, L10, NTC, NH, K496 and similar.
How do I install the seal?
Remove the old seal, clean the hub surface, apply a thin layer of compatible lubricant, and press the new seal into place ensuring it seats evenly. Refer to the vehicle service manual for torque specifications.
Is this seal covered by a warranty?
Yes, BLKPRO provides a limited one‑year warranty against manufacturing defects when installed according to the recommended procedures.
Can I use this seal on non‑diesel engines?
While primarily designed for diesel applications, it may be suitable for other engines with matching specifications. Verify dimensions before use.
What is the best way to store the seal before installation?
Keep the seal in a cool, dry environment, away from direct sunlight and chemicals. Store it in its original packaging until ready to install.




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