SKF 23685 Timing Cover Seal Instruction Manual

1. Product Overview

The SKF 23685 Timing Cover Seal is engineered to provide reliable sealing performance in automotive applications. This seal is designed to prevent lubricant leakage and protect internal components from contaminants, ensuring the longevity and efficient operation of the engine's timing cover area. SKF seals are developed with advanced materials and design principles to withstand demanding operating conditions, including varying temperatures and aggressive lubricants.

Figure 1: Front view of the SKF 23685 Timing Cover Seal, showing the primary sealing lip and spring.

Key features include a robust seal lip profile that meets or exceeds original equipment (OE) specifications, ensuring effective exclusion of dirt and contaminants. The sealing element is constructed from synthetic rubber blends formulated to operate in temperatures ranging from -40°F to 400°F, and is compatible with modern lubricants containing aggressive additives. The case components are made from high-grade carbon steel with a phosphate coating for rust protection, and most metal-cased seals are coated with Bore-Tite to fill housing bore imperfections and ensure a leak-proof seal.

2. Specifications

3. Installation Guidelines

Proper installation is crucial for the optimal performance and longevity of the SKF 23685 Timing Cover Seal. Follow these general guidelines:

1. Preparation: Ensure the shaft and bore surfaces are clean, smooth, and free from burrs, nicks, or corrosion. Any imperfections can compromise the seal's effectiveness.
2. Lubrication: Lightly lubricate the seal's inner lip and the shaft with the appropriate lubricant (e.g., engine oil or assembly lube) before installation. This reduces friction during installation and helps prevent damage to the seal lip.
3. Alignment: Carefully align the seal with the bore. Avoid cocking the seal during installation, as this can lead to uneven pressure and premature failure.
4. Installation Tool: Use a dedicated seal installation tool or a suitable driver that applies even pressure around the outer diameter of the seal. Never strike the seal directly with a hammer or use tools that could deform the seal case.
5. Seating: Drive the seal squarely into the bore until it is fully seated. Ensure it is flush with the housing or seated to the specified depth according to vehicle manufacturer instructions.
6. Inspection: After installation, visually inspect the seal to ensure it is not damaged, twisted, or improperly seated.

Figure 2: Rear view of the SKF 23685 Timing Cover Seal, showing the metal case and Bore-Tite coating.

Important: Always refer to the specific service manual for your vehicle or equipment for detailed installation procedures and torque specifications.

4. Operating Principles

The SKF 23685 Timing Cover Seal operates by creating a dynamic seal between a rotating shaft and a stationary housing. Its primary function is to retain lubricants within the engine's timing cover and prevent the ingress of external contaminants such as dirt, dust, and moisture.

• Sealing Lip: The precisely engineered seal lip maintains continuous contact with the rotating shaft. The spring-loaded design ensures consistent pressure, adapting to minor shaft eccentricities and wear over time.
• Material Composition: The polyacrylate seal lip material is selected for its resistance to high temperatures, engine oils, and various automotive fluids, ensuring chemical compatibility and long-term sealing integrity.
• Case Design: The robust carbon steel case provides structural rigidity and ensures a secure press fit into the housing bore. The Bore-Tite coating on the outer diameter helps to seal minor imperfections in the housing, preventing static leaks.
• Contaminant Exclusion: The design of the seal lip also acts as a barrier against external particles, protecting the internal engine components from abrasive wear.

5. Maintenance and Inspection

Once installed, the SKF 23685 Timing Cover Seal is designed for maintenance-free operation under normal conditions. However, periodic inspection during routine vehicle servicing can help identify potential issues early.

• Visual Inspection: During engine maintenance, visually inspect the area around the timing cover seal for any signs of oil leakage. A slight film of oil might be present, but active dripping or significant accumulation indicates a potential issue.
• Shaft Condition: If the seal needs replacement, inspect the shaft for wear grooves, pitting, or damage that could compromise the new seal's performance. Address any shaft imperfections before installing a new seal.
• Environmental Factors: Ensure that the engine compartment is kept reasonably clean to prevent excessive dirt and debris from accumulating around the seal, which could accelerate wear.

6. Troubleshooting Common Issues

If a leak occurs after installation or develops over time, consider the following potential causes:

• Improper Installation: The most common cause of seal failure. This includes damaging the seal lip during installation, installing the seal crooked, or not seating it fully. Review installation steps carefully.
• Damaged Shaft Surface: Grooves, nicks, or excessive wear on the shaft where the seal lip rides will prevent a proper seal. The shaft may need repair or replacement.
• Incorrect Seal Size: Using a seal with incorrect dimensions for the shaft or bore will lead to immediate or premature leakage. Verify the part number.
• Excessive Crankcase Pressure: High pressure within the engine crankcase can force oil past seals. Investigate and resolve any PCV system issues or engine blow-by.
• Seal Material Degradation: While SKF seals are designed for durability, extreme operating conditions or very long service life can eventually lead to material hardening or cracking.
• Contaminant Damage: Abrasive particles entering the seal area can wear down the seal lip prematurely.

If a leak persists after reviewing these points, professional automotive diagnosis and repair are recommended.