Vikfin specializes in tthe sale of used excavator parts. We buy up 20- and 30-ton machines, then strip them down and sell the component parts. More than half of the units we sell are undercarriage parts. For obvious reasons, the undercarriage takes the brunt of the operating load. The last thing you want to happen when you buy a used excavator is having to fork out large volumes of cash to replace undercarriage components. Here are a four things to look for before you pull the trigger and invest in a used machine.
1) Tracks
Tracks are the first parts we sell when we strip a machine. We typically having a waiting list, especially for 20-ton 190mm pitch tracks. Twenty-ton tracks are universal to all makes of machines. Tracks from a CAT 320D, will fit onto a Komatsu PC200, a Volvo EC210, a Hitachi ZX200, a Case CX210, Sumitomo SH210 etc.
When you inspect the tracks, there are numerous things you want to look at. The bushings and pins should be as round as possible. C shaped bushings indicates wear on the tracks and the need for replacement, depending on how pronounced the C shape is. If the bushings have been worn through and you can see the pins, the life on the tracks is limited. You also want to check for play in the grousers/shoes. Jump onto the tracks and use your own body weight to see if there is any movement on the shoes.
2) Final Drives
You want to drain the oil from both drives and check for metal filings. Remember that metal filings will settle at the bottom of the drive. If your oil plugs are off the bottom, move the machine forward so that you can inspect the oil at the bottom. You also want to pay attention to the color of the hydraulic oil – new oil is amber/gold while old oil is inky black. If the oil is new, it is possible that a less than scrupulous seller has filled the drives with new oil to mask a problem. If the oil is inky black, it may indicate that the seller has not been all that diligent in maintaining the drives.
Then you want to take off the final drive covers and inspect the sun gears and the planetaries. You what to look for two things on the gears. Firstly, you don’t want to the teeth on the gears to be sharp, you want them to be flat. Secondly, you also want to look for chips or nicks on the gears. The smoother and flatter the gears, the more life you are going to get out of the final drives, which are very expensive parts to replace.
3) Sprockets
As with the gears in the final drive, you want to pay close attention to the teeth on the sprocket of the final drive. The sprocket is the point of contact of the final drive to the tracks and therefore subject to considerable wear and tear. You do not want these teeth to be too sharp. You want the teeth to be deep and flat – you do not want them to be shallow and sharp.
4) Track Tension
Tight tracks on larger tracked machines will increase pin, bushing and sprocket wear, triggered as the bushing rotates and/or slides in the sprocket. Loose tracks are a big concern as it leads to de-tracking which will cause component failure or breakage; as well as compromised site safety. The result is unplanned, unwanted downtime; costing time and money. It is better to have tracks that are too loose than too tight. When you are buying a used machine, be on the lookout for tracks that are too tight because that could point towards additional wear on the pins, bushings and sprockets.
#heavyequipment #construction #excavator #heavymachinery #constructionequipment #heavyequipmentlife #caterpillar #earthmoving #mining #excavation #komatsu #equipment #heavyequipmentnation #cat #digger #excavators #demolition #heavyequipmentoperator #machinery #constructionlife #engineering #truck #concrete #bulldozer #earthmovers #constructionmachinery #civilengineering