🛠️ How to Change the Input Shaft (HSS) Oil Seal – Step-by-Step Guide
At GearboxBuddy, we understand the importance of precision maintenance for gearboxes and drive systems. One common service task is replacing the input shaft oil seal (often called the HSS seal). This seal prevents oil leakage and protects your gearbox’s internal components from contaminants. Here’s a clear and practical guide to help technicians carry out this job efficiently.
🔧 Work Preparation
- Remove the Key from the input shaft to avoid damage during disassembly.
- Clean the input shaft surface to remove dirt, oil, and debris.
- Detach the oil seal cover from the gearbox housing.
- Extract the old oil seals from the cover.
- Clean the oil seal mounting surface on the cover using fine sandpaper, ensuring no burrs or damage.
- Scrape or sand off any old Loctite residue from the seal cover.
🧰 Installation Procedure
Shaft & Surface Inspection
- Ensure the input shaft sealing surface is smooth and undamaged.
- Check for burrs along corners and keyway – remove them if necessary.
- Wipe the shaft clean with a cloth.
Protect the Seal During Installation
Use electrical insulation tape to cover sharp edges on the shaft and keyway – this protects the new seal during installation.
Installing the New Oil Seal
- Apply a thin layer of Loctite 574 to the oil seal mounting surface.
- Mount the new oil seals into the cover, ensuring a flush and perpendicular fit. Refer to assembly drawings for special seal arrangements.
- For Double Lip Seals, apply a bit of grease between the seal and dust lips. For Single Lip Seals, grease only the seal lip.
- Add a light grease layer to the shaft surface as well.
- Reinstall the seal cover onto the gearbox housing carefully, ensuring the seal lip doesn’t fold.
Pro tip: For difficult fits, you can fabricate a special installation sleeve to guide the seal into place.
✅ Final Check
After installation, rotate the shaft gently to verify seal alignment and smooth movement. Double-check for any signs of folding or misalignment before operating the machine.
📌 Why It Matters
A damaged or poorly installed HSS seal can lead to:
- Gearbox oil leakage
- Shaft wear
- Premature failure of internal components
By following these best practices, you ensure long-term reliability of your gearbox system.
If you’re sourcing quality oil seals or need expert support for gearbox servicing, feel free to contact us at GearboxBuddy – your trusted partner for industrial drivetrain solutions.
