Tracked Undercarriage, Excavators

[John C.]

I've been doing what I can to pass on information that I've learned through years of maintaining, repairing, inspecting and appraising machinery. When I get time I like to build a short video projects that can show anyone that wants the information the kinds of things I look for and then try to interpret what I see. I've doing these short programs since the 1990s and plan on passing on what I can before the brain cells start to fade. Here is the latest project I completed yesterday. Please like the program if it suits you or comment on what other information you would like to see.

Thanks for your support!

 

[mitch504]

That was a good video, John. They ought to make it required viewing before bidding on one at auction.

I had a salesman almost convince a customer of mine that the machine had 90% undercarriage, I finally just told him "You asked me to come here for a reason, if you are going to listen him then I am leaving, I already did my job when I told you the rails and sprockets were shot."

The grousers were high and the sprockets had good paint, though. He tried to say they were made with pointed teeth.

 

[Coastal]

Great video John!

 

[John C.]

Thanks for the positive comments. I'm trying to find subject machines for a dozer video next.

 

[DC&E]

John, great video, as one gentlemen said this ought to be a required video before buying or inspecting any track vehicle.

 

[mitch504]

John, great video, as one gentlemen said this ought to be a required video before buying or inspecting any track vehicle.

Naw, that wasn't a gentleman, that was me!

 

[John C.]

You are all gentlemen until proven otherwise.

Thanks again for the comments!

 

[CM1995]

Well done John! Thanks for taking the time to make the video and sharing.

 

[Shawn Hoff]

Great video, John! Very helpful and informative.

 

[John C.]

Thank you all for the comments.

 

[Bentsteel]

very professional john, do you have any video on mini excavator's that use rubber tracks?

 

[John C.]

It's in the plans but the phone hasn't quit ringing for the last month and a half and I haven't been able to turn down a paycheck. When the sunshine comes out again I plan to go back to video production.

 

[wee_gus]

John, are you an undercarriage expert?

I need some advice on an 2006 JCB JS145LC,

customer replaced track chains, sprockets, idlers and recoils, too and lower rollers, 12 months ago, now for some reason machine has been eating the lower rollers. Since jan when replaced it’s gone through 4 sets of lower rollers, the all seem to seize up, tried different manufacturers and all ends up the same, usually getting 3-4 months out of a set

 

[John C.]

Seizing rollers indicate bad oil seals or something in the soil getting forced into them and pushing them apart. You should probably look at the application and materials the machine is working in. What are the names of the manufacturers that supplied the bottom rollers? Have you contacted them and have they been paid the warranty on the failed rollers?

 

[fastline]

Question - how do you 'quickly' assess the UC component's condition as a percent? Is this usually just an estimated value? What I have done in the past is physically measure components and compare to new spec, and do the math.

Right or wrong, what I have done is say chain new spec is 9" for a series of chain pins (3" pitch we will say), and 9.750" is shown as the wear limit or 0% life. If I measure 9.375", I would call that 50%.....

However, there is no way, when looking at prospective machines to buy, I have time to look up every machine, get those values, and go through this process. Is there a better or faster way?

Now, I am not a total idiot, and certainly have assessed UCs based on visual markers as you have done, such as looking very first at sprockets.

Also, one thing you might wish to mention is checking for turned bushings. This is an indication that chains have already reached "the end" on one side and reaching in to find flats on the back side of the chain bushings (no other way for them to get flats) indicates turned bushings so check further on chains.

 

[jhark123]

Excellent video.

 

[John C.]

fastline, all good points. On figuring percentage of wear, you can only do it when you have a spec that says at what point the component is 100% worn. When you have that, it's just basic math and percentages. The visual markers though will give you most of what you need to know. Front idler position, sprocket tooth thickness and bottom roller clearance on the track pin bosses only take seconds to look at.
Turning bushings has become a thing of the past now because of SALT tracks. For dozers, it doesn't pay to do it on anything smaller than a D8 dozer. In order to make it pay, you have to do a wet turn which means at least half of the seals need to be replaced and all the links need to be filled and tested. It is an expensive process to go through for a few hundred hours of use. For excavators, the chain links will have been shock loaded enough that the pin bores will never hold the press fit required to hold the chains together again. The chains themselves will also be extremely beat up. It is something I check for but left out to the video programs for the above reasons.

 

[wee_gus]

Seizing rollers indicate bad oil seals or something in the soil getting forced into them and pushing them apart. You should probably look at the application and materials the machine is working in. What are the names of the manufacturers that supplied the bottom rollers? Have you contacted them and have they been paid the warranty on the failed rollers?

machine is working on various soil conditions normally working in Forrest applications.

Suppliers have been MST, AsTrak, & someone else, all of whom have replaced the rollers FOC

 

[John C.]

I don't know of those suppliers. I looked up AsTrak and see that they are dealing Berco for some stuff. What does FOC mean?

 

[wee_gus]

I don't know of those suppliers. I looked up AsTrak and see that they are dealing Berco for some stuff. What does FOC mean?

astrak do, Berco, duratrak, their own brand, and K trac.

mat have supplied ITR parts.

FOC- Free of Charge