Track link wear?

[Jeff D.]

I was inspecting my JD350 tracks, in anticipation for grouser repair/replacement, and I measured the pin & link wear. The pins are under 25% total wear(over 75% left)when measure across a 4pin span, but the link wear is at 75%.(3" when measure from grouser to bottom edge)

How fast do links wear under normal use? Are they alot slower than pin wear?

Can I run these links out too 100%. I hate to rebuild the tracks when there is so much life left in the pins. The sprockets are very good shape too.

I've the feeling that the old links and grousers where fitted with new pins when they also should've been changed out, but what to do now?

Opinions?

 

[Ford LT-9000]

If your looking for extra traction buy some grouser bar stock and weld some new grouser bars to your current pads. Around here we usually run tracked machines till the tracks fall off. When it comes time to change things everything is done new chain new pads new sproket,idler bearings etc.

A chain will wear out when the bottom rollers stop rolling and if you keep your tracks at proper tension nothing gets into a bind.

 

[Wulf]

Jeff,

When you are checking across 4 links (actually the distance between 5 pins) you are checking internal pin and bushing wear. You need to tension the links slightly by backing a piece of lumber or something between the sprocket and track and then applying the brakes or having someone keep the machine from rolling while you measure the 'stretch'

Another critical measurement is bushing external wear (where the sprocket drives it) when the bushing becomes worn it may crack or break.

You can get the pins and bushings 'turned' to extend pin and bushing life but it's expensive and as you indicated if the link height is worn more than 50% its not cost effective.

Many dozer chains are sealed and lubricated (SALT) which means they have heavy oil in them and internal pin/bushing wear is normally low - you can normally tell SALT links because they will have a rubber or plastic plug in one end of the pin (where the oil is pumped in)

On well maintained SALT chains the critical measurement and controlling factors are normally external bushing wear or link height depending on the type of work you do and the soil and terrain you work in.

In my experience bushing wear normally exceeds link wear and grousers normally wear at half the rate of the link assy's.

Like Ford says it may pay to just run them out if you confirm that the wear is really 75% and start to save up for a replacement undercarriage

 

[Jeff D.]

I didn't think of putting a chunk of wood into the sprocket, but I did put a jack into the track and lifted it tight in the center to measure the 4 pin distance(actual 5 pin span).

I'm not "up" on dozers very much, but here's my sprockets and roller pics. I know it's hard to judge from a pic, but to me they seem alright. Any thought's??

I think I may just run them out, and skip doing the grousers for now. I hate to stick any money into them if I'll be repalcing the tracks in the future.

 

[Ford LT-9000]

The sprocket and chain looks okay the teeth are not worn to a razor sharp edge :laugh

When the tracks really start crunching and squeeking then its time to get worried. The old 963 Cat I used to run the tracks were so worn out the sprocket used to skip and jump in the chain.

Aslong as the bottom rollers and the idler are still rolling and no flat spots your good to go.

 

[Wulf]

Tell you what Jeff... don't worry about not being 'up' on dozers... undercarriage measurement, analysis and management is very very tricky.

After looking at the pics the sprocket, links and bushings look OK to me. There are no 'shiny parts' which is a good sign!

One thing to check though is the condition of the bottom (track) rollers As both the roller treads and the link tread wears the wear accelerates and the roller outer flanges can come into contact with the track pin bosses. This probably isn't happening on your machine but you can possibly see some progression.
When this happens the impact of the flanges thumping the boss can allow the pins to start to come loose. I've seen new track links be installed with worn out rollers and they haven't lasted more than a few hundred hours.

BTW... I just looked again and it looks like you have a loose pin (master pin???)

 

[Jeff D.]

BTW... I just looked again and it looks like you have a loose pin (master pin???)

It may a master pin, I'm not sure. It is recessed, but it isn't "loose". I'll be keeping an eye on it though.:yup

Thanks for the help guys. I'll make sure all rollers are turning, keep greasing them, and just run it.:thumbsup

 

[Jeff D.]

FWIW, If anyone needs to determine their dozers track wear, I found this site that has the specs for tracks on most dozers, and it also explains how too measure them.

http://www.crawlerheaven.com/tracklinks_chart.htm#John Deere