Without doubt, one of the most pervasive pieces of heavy construction equipment today is the crawler tractor. If you are looking to buy a used crawler tractor, it is especially important to know what to look for when you inspect the tractor so you can make an informed, confident purchasing decision.

First Things First: Inspecting the Blade

There are a wide variety of crawler tractor blades, each designed to meet a specific need. Regardless of the blade type – straight, universal, push block, angle, etc. – the following general blade inspection guidelines need to be kept in mind:

  • The Blade Face & Cutting Edge
    Visually check the top of the blade, including the spill guard, for any signs of damage caused by heavy materials such as rocks and other types of materials. Next, look for any plate lines on the blade face itself. Plate lines can be seen on refaced blades, indicating that blade has been repaired due to excessive wear and tear. Inspect eh bottom sides of the blade as well as the corner bits and cutting edge for corrosion, welding and other signs of excessive wear.
  • The Blade Cylinders and Push Arms
    Carefully check the blade push arms, with particular attention on trunnion pins and caps. If the trunion cap seems loose or there is space between the cap and the trunnion, it’s a good bet that it has been subjected to excessive wear. Look at both push arms for signs of scarring, as well as the hydraulic cylinders and rams for leaking seals, scratches or dents. This is particularly true for Semi-U or Angle blades.

Checking the Undercarriage

Clearly the most important part of any crawler tractor, you need to take your time inspecting every component of this part of the tractor. As well as being the most important part of any crawler tractor, it is also the most expensive part of the tractor to repair.
Uneven carriage wear can result from a number of operational factors so it’s important when looking to purchase a used crawler tractor to check both sides of the undercarriage to accurately gauge it’s operational condition.

Rails, Chains, Rollers & Idlers

Starting with the rails, feel the tops and bottoms of the bushings attached to the rail links. Does the busing have an optimum round shape or is it more compress and oval in shape due to wear and tear? Where does the wear occur: only on the bottom, or also on the top of the bushing? Wear on the top of the bushing indicates that the bushings and pins have already been turned which is a sign that they are more than half way through their operational life and will need to be replaced sooner rather than later. Excessive spread can indicate internal pin wear, as well.
Next look at the slack adjuster to see how far it has been extended as an indication of internal wear.

Next comes the rollers, both top and bottom. Look for cupping where the rollers contact the rails. Look for excessive flange wear. Look for surface wear on the idlers, especially the overall out idler edge thickness to see how much wear they have sustained.


Just like with the idlers, check the condition of the sprockets. Check the segment teeth to see if they have a sharp, pointed shape or appear to be noticeably thin.

Track Pads

When it comes to track pads, it all boils down to the plate thickness and grouser bar height. Once the grouser bar is basically level with the pad bolts, it’s time to think about replacing or rebuilding the track pads. Elsewhere on the undercarriage, be sure to check the track frame, stabilizers and sway bars for scarring, indicating wear from contact with hard materials.

The Engine and Hydraulic System

Get inside the engine panels and check for any obvious engine leaks, dirty filters, and loose belts. Inspect all fluid levels. Look under and around the machine for leaks. Check every hydraulic cylinder for signs of damage and leaks. Pay particular attention

Fire it Up: Overall Operation

Now it’s time to start up the machine and check the exhaust coming out of the stack. Look for dark color exhaust, any buildup of carbon, or any other signs of needed engine service. Other considerations include any cab heating or air conditioning features, and whether they work as well.

As with any piece of heavy construction equipment, ongoing maintenance is the key to ensuring that your equipment gives years of worry-free, trouble-free service. At Construction Parts HQ, our business is making sure your heavy construction equipment stays up and running. We specialize in construction equipment parts for all popular makes and models of construction equipment parts. Find the crawler tractor parts you need at Construction Parts HQ.