Drive Axle Inspection on a Big Rig

The name "Drive Axle Inspection" may seem a bit daunting to some, especially if you aren't familiar with axles on a big rig. However, it’s important to understand how an inspection works because it is a Federal requirement to inspect the vehicle before driving each day. Normally, this takes about 15 minutes.

Components to Inspect

The checklist of parts consist of:

  • Lubricant level to confirm volume is correct
  • Wheel seals
  • Pinion output or input seals to check for oil build up or dirt
  • Carrier-to-housing connection
  • Make sure the housing breather isn’t missing or damaged

Side note: the axle lubricant and seals require a more attentiveness than the axle housings. You simply need to look for any damaged welds or loose mounting hardware when inspecting the axle housings.</p>

Housing Breather

Inspecting the breather is an important part of this procedure due to the fact that a wrecked breather could let contaminants into the axle, putting the lubricant at risk. However, if the breather is clogged, heat in the axle might cause pressure inside the housing pushing lubricant out through the wheel or pinion seals, which leads to a false diagnosis of a seal failure.

The breather permits a tiny amount of vapor to let out from the axle, and the section surrounding the breather might look moist or immersed in dirt. Don’t be alarmed if you notice this because specialists say that a small amount of moisture surrounding the air vent on the axle is usual. However, if you notice immoderate moisture you should utilize thread sealant to end the leaking.

Call Us for Drive Axle Inspection, Drive Axle Repair & U-Joint Maintenance

Misaligned axles can be extremely problematic causing issues with tires and a misdiagnosis. So it’s important you’re checking your vehicle’s alignment when doing a drive axle inspection.

A simple way for checking if your drive axles are correctly aligned is to compare them to each other through measuring them and the frame. Follow these steps:

  1. With the brakes released, make certain that the wheels are jammed in choks.
  2. Measure the separation between the axles. (They should be similar on both sides)
  3. Estimate the space from a fixed point on the axle, such as the brake spider, to the frame rail. (They should match up as well)

If they are not similar, a full-chassis alignment job may be necessary for your drive axles