A failing oil seal rarely announces itself loudly — it leaks quietly, and by the time you notice, the damage may already be done. Here are five signs to catch early.

1. Grease or oil weeping around the hub

A thin film of oil on the inside of the wheel or around the hub flange is usually the first sign. Check at every service.

2. Oil on the brake drum or shoes

If brake performance drops and you see oil inside the drum, the seal has failed and the lining is contaminated — both must be replaced.

3. Low axle oil level

Regularly topping up axle oil points to a leak. Investigate before the bearing runs dry.

4. Unusual hub temperature

A hot hub after a normal run can mean lost lubricant and metal-on-metal contact. Stop and inspect immediately.

5. Visible seal damage

Hardened, cracked or cut sealing lips mean the seal must be replaced — and the shaft surface checked for wear or pitting.

Prevention is cheaper than repair

Use quality axle oil seals, correct installation tools and the right lubricant. Popular OEM oil seals such as 23710, 35058, AE7943E and 20212133001 are available from UIB Truck Parts at factory-direct prices.