Mind your axle to prepare for the unexpected

Mind your axle to prepare for the unexpected

Finding the root cause of leaks is important, even if the surfaces and gaskets appear to be in good condition.

If it ain’t broke, don’t fix it. Cliché? Well, yes, one would be hard-pressed to find a technician who does not hold a familiarity with that alleged truth. When first considered, the concept in the proverb makes good sense. Granted, the drive to improve vehicle operation has led to virtually thousands of innovations. Little chance exists that inquisitiveness will, or even should be, driven from the technical mind. But what about the “don’t fix it”?

The story of my great-grandpa and his Caterpillar Twenty tractor comes to mind. The operator’s manual indicated an oil change and lubrication service should be performed once a year, regardless of how many hours the tractor was operated. So, religiously following the maintenance instructions, he would go out and change the oil and pump grease in all the required fittings. Never mind that the tractor had not been started, much less operated, over the last year.

Did grandpa’s tractor maintenance schedule help or hurt anything? Other than the cost of materials and quite a lot of old grease oozing out of various points, probably not much harm done. Of course, I cannot discount the fact that I still used (to?) shake hands with the old Cat, discing up the field into the late 1990s until it was sold to a tractor collector.  

With today’s trucks, there are major components that tend to be ignored because they are largely trouble free – drive axles, for example. As long as there is no oil dripping on the ground or odd noises during operation, making sure the axle has sufficient lubrication is typically all the attention a drive axle gets.

Since an axle does not burn oil, then any reduction of oil in the axle is likely the result of a leak. Over time, sealing surfaces on rotating parts wear, creating a point for a potential leak. Gaskets and seals grow brittle and crack. Consequently, an important part of any axle maintenance is to check for leaks as well as signs of a developing leak.

While repairing leaks is key to helping the axle live a long, happy life, finding the cause for the leak remains just as important. Wear and damage are easy enough to identify. But what if the sealing surfaces and gaskets look good?

One point to inspect whenever addressing an axle leak is the inconspicuous vent. As an axle operates, heat develops. As the air in the axle assembly heats up, it expands and will escape through the point with the least resistance to maintain that pressure.

Thus, the axle vent. The vent is typically placed somewhere at the top of the axle housing and may be attached to the end of a hose, reaching higher up to the frame rails. If at any time this vent or hose  gets smashed or plugged up, the heated air will try to escape through seals and gaskets causing an oil leak.

While there is hardly a need to reinvent the vent, taking a look at the vent and vent piping for issues when checking the axle oil level makes for a simple maintenance step that could help keep the truck in service.           

You May Also Like

Percentage of female techs increases

The 2023 WIT Index shows that more than 7% of technicians in companies in transportation are women, the association stated.


According to new data from the ,Women In Trucking Association (WIT)'s 2023 WIT Index, the percentage of female equipment technicians in corporations with for-hire or private fleets in the commercial freight transportation industry has shown a substantial increase. The 2023 WIT Index shows that more than 7% of technicians in companies in transportation are women, a number that reflects an increase of nearly 4% from the reported 3.7% of women in technician roles in the 2022 WIT Index.

Peterbilt Technician Institute Nashville inaugural classes begin

Upon completion of the advanced program, students will earn factory-trained technician credentials.

HDA Truck Pride adds Idaho’s Diesel Depot to its network

Diesel Depot has grown substantially over the years to 45 employees and a 25-bay shop.

Volvo Trucks names 11 new certified EV dealers

Volvo’s North American dealer support network for battery-electric trucks now includes 47 certified dealership locations.

Heartland Express receives SmartWay High Performer Award

The SmartWay High Performer Award recognizes companies who producesz more efficient transportation solutions.

Other Posts

Five truck trend takeaways from November

The biggest stories from November focused on the latest truck trends, all in one place.

The fuel efficiency faceoff begins!

The battle to earn the CDL is over, but the fight to crown a fuel efficiency champion is just getting started.

Taking the commercial driver’s license test

After struggling with shifting, the CDL test is ahead on this episode of the Fuel Efficiency Faceoff.

How to avoid the effects of harsh winters on your truck’s batteries

The time to avoid winter’s effects on the truck’s batteries is actually in the summer, not the winter.