If the axle seal on your car is worn or broken, you'll be able to tell easily. You'll notice an oil spot on your driveway that gets larger day by day. However, leaking oil can spell trouble for a differential and more importantly, your transmission. In this article, we'll explore what happens when this part develops a problem. I'll describe how to identify it and fix it.

Differences: An Overview

Your vehicle's differential is the part that takes the power coming from the transmission and drive shaft, and splits it between two wheels. In doing so, each wheel is allowed to turn at different speeds with equal torque.

In any car, the gears within the differential are required to mesh at very high speeds, so the fabrication tolerances are extremely small and the lubricants are well-suited to "high shock" environments. Secondly, since the differential is connected to the transmission, the axle seal and gear oil function to keep rocks, dirt, and other debris from entering and causing serious damage.

Signs Of A Faulty Axle Seal

Many fluids can drip from your car and should be inspected accordingly, but a broken axle seal causes gear oil to drip. Gear oil has a distinct smell similar to rotten eggs (because of the sulfur content). In addition, gear oil is much thicker than similar lubricants in order to protect the gears as they move at high speeds. The viscous fluid is engineered to stick to the gears, providing maximum coverage and lubrication.

In many cases, a seal break is not the product of driver error or carelessness, but rather the actions of a mechanic or someone on the assembly line in the factory. If the axle is improperly removed or replaced, the seal is likely to rip in the process.

Replacement Of The Unit

To replace the torn seal, first pry it out of the differential. You can accomplish this by hand, but the better solution is to use a seal removal tool. Once you remove it, grab the replacement part and installation tool. Each installation tool will come with a set of rings; choose the one that is able to fit snugly into the mount point and slightly smaller than the seal itself. Finally, insert the tool into the mount on the differential and firmly tap with a hammer to fix the part. If you accidently tap it too hard, the replacement could become deformed or tear a second time.

Depending on your vehicle, test the differential movement after the install to ensure everything is meshing properly. Then, replace the differential cover and reinstall the axle. As a final precaution, take the car for a quick drive to make sure everything is working correctly.

If you have worked on cars before, you should be able to perform this job easily. Of course, as I always suggest, take your vehicle to a trained mechanic if you're not sure of your ability. When it comes to this part, spending a few dollars is worth the peace of mind.