Hard facing 17 ton excavator undercarriage rollers

[DAPPH]

Do you know if there is still some adjustable distance to go on the track adjusters Are the tracks & track pins too worn to take a link out once you redo the rollers .

If they are fully out and the tracks are so worn that you can't get any more workable tension on the track , the drive sprockets will forever be jumping inside the tracks , often leading to a thrown track as you turn or reverse whilst turning.

On the tracked excavators ....we could usually get a part worn set of tracks and rollers in good nick for about £ 1500 inc vat.... already taken off waiting for collection. So long as we went from Wisbech to Nottingham to pick them up... they'd last about 15 months on the landfill rubble ,walking and tracking it in & generally using the excavators as loading shovels or shaping the mounds of graded & ungraded concrete & brick etc.
By the time I'd changed them over they were just prime scrap steel .

Track pins were often so badly worn that they were like half shouldered bolts , putting in a new link or more often taking one out usually saw me having to fit new pins . Occasionally the pins were so far gone they'd shear , then the work really started. Especially if the excavator was on a steep batter with a track opened up .

 

[Bill Edwards]

I'm imagining that the seals will be long gone TBH, it spent a good whack of its 20 years in a sand quarry and as we all know, that stuff gets everywhere!
Replacing rollers alone may not even solve the problem as the chain is worn-it would be right to replace the chain and rollers at the same time. Now that would be a fair old cheque to write.
Getting ready to hit this job with confidence now. It won't however be putting my kids through college

Not just the chain and rollers, but also the drive sprocket and quite possibly the front roller too!
The cost probably doesn't bear thinking about!

 

[Bill Edwards]

On the tracked excavators ....we could usually get a part worn set of tracks and rollers in good nick for about £ 1500 inc vat.... already taken off waiting for collection. So long as we went from Wisbech to Nottingham to pick them up... they'd last about 15 months on the landfill rubble ,walking and tracking it in & generally using the excavators as loading shovels or shaping the mounds of graded & ungraded concrete & brick etc.
By the time I'd changed them over they were just prime scrap steel .
Track pins were often so badly worn that they were like half shouldered bolts , putting in a new link or more often taking one out usually saw me having to fit new pins . Occasionally the pins were so far gone they'd shear , then the work really started. Especially if the excavator was on a steep batter with a track opened up .

Interesting - I've a 7 ton loading shovel with tracks which are totally worn out. I don't think the pins are about to snap, but some of the bushes which run on the sprocket are breaking up.
The problem I've had is keeping the damn things to stay in place, there's so much wear and slop in them that they'll derail at the drop of a hat - they'll come off while turning, while going over stones, while just tracking straight... etc. They could slip off every 10 minutes - the trick being to feel it and stop, take a look and work the machine in the right direction to slip them back on before they're laid at the side.
Building up the sprocket and front idler, plus running them as tight as they'll be forced, has greatly helped in that they've nowhere to go, but they still need watching.

When running tracks to total destruction, did you not have these problems?

 

[TechnicAl]

I wouldnt go for that rod...........but if thats what you can get.....who am I

remember that composition is All Weld Metal which will need 3 passes to achieve

I would go for the higher Cr and C content, single pass and no preheat.......but to be honest its a guess..........it always is with this kind of stuff

 

[J.B. Welding]

Not just the chain and rollers, but also the drive sprocket and quite possibly the front roller too!
The cost probably doesn't bear thinking about!

She had a new sprocket about 2 years ago on that side, he bought that of his own free will and I fitted it-that's when I noticed the old one was on backwards..

Bushes are showing some holes, There was a problem with pins coming out a couple of years ago, I got called out two or five times to put the track back together then we decided to weld both sides of all the pins and that was the end of that.
Yea the tracks come off pretty easily, worst time was when it was sunk in a wet hole in the forest, but tightness made him learn not to take it off too much, and keep checking the tension in the tracks.
Wish I had a pic of the state of the chain for comparison to what you chaps call scrap worthy-in time I shall hopefully.

Come to think of it, if I can keep it going long enough maybe this old digger will help put my kids through college, or at least pay their dinner money

I wouldnt go for that rod...........but if thats what you can get.....who am I

remember that composition is All Weld Metal which will need 3 passes to achieve

I would go for the higher Cr and C content, single pass and no preheat.......but to be honest its a guess..........it always is with this kind of stuff

I guess 3 passes will help give me a good thickness of build up without using 7018s in the equation?

 

[DAPPH]

Interesting - I've a 7 ton loading shovel with tracks which are totally worn out. I don't think the pins are about to snap, but some of the bushes which run on the sprocket are breaking up.
The problem I've had is keeping the damn things to stay in place, there's so much wear and slop in them that they'll derail at the drop of a hat - they'll come off while turning, while going over stones, while just tracking straight... etc. They could slip off every 10 minutes - the trick being to feel it and stop, take a look and work the machine in the right direction to slip them back on before they're laid at the side.
Building up the sprocket and front idler, plus running them as tight as they'll be forced, has greatly helped in that they've nowhere to go, but they still need watching.

When running tracks to total destruction, did you not have these problems?

Yes Bill some times I had to put the track back on four or five times a day.
One day the dopey operator decided to pump the adjuster with an " Oddy gun"....a high pressure hand operated grease pump, as the track tension was not to his liking .
It and the sprockets were far too worn to get any worthwhile adjustment that meant anything , he pumped too much & forced the hydraulic track adjuster piston out through the closed end of the adjuster .. result the track came off totally used the bulldozer to recover the digger on a steep batter to level ground to see what was wrong , the front roller also slid out . Earragh .. I finally convinced Guy that getting a £2k scrapper was a better option than trying to repair a scrapped scrapper. Enter the Hymac .

 

[TechnicAl]

S


I guess 3 passes will help give me a good thickness of build up without using 7018s in the equation?

The best rods can produce an almost square deposit about the same thickness as the rod diameter. Ideal for build up. Maybe a bit spattery but thats the pay back.
The high Cr + High Carbon may be limited to 2 passes and dont worry if the weld cracks..........its called check cracking and providing its not underbead it provides a sort of stress relief........if you can see the cracks they are not underbead